You may not have known it, but May 27, 2004, was Meryl Streep Day. Or so proclaimed Manhattan Borough President C. Virginia Fields, kicking off a luncheon at the Marriott Marquis in Midtown that day. It was one tribute in an afternoon full of them, all intended to honor Ms. Streep’s receipt of a Career Achievement Award from New Dramatists – a slightly odd prize, considering that New Dramatists is an organization devoted to nurturing young playwrights, and Ms. Streep has appeared in a play only once in the last 22 years. Still, she’s a big draw; her recent pile-up of honors includes a Stanislavsky Prize, an American Film Institute Life Achievement Award and the usual raft of Golden Globe, Oscar and Emmy nominations. Standing in a spotlight inches from Ms. Fields, who was ticking off some of these achievements, Ms. Streep tried on every expression in her playbook – horror, incredulity, madcap goofiness – in what appeared to be an attempt to distract the 800 guests (and herself) from the incongruous tone of civic import. Finally she just raised her arms in a gesture of exultation, or crucifixion, and got a laugh at least. “You would think they could have suspended alternate-side-of-the-street parking on my behalf,” Ms. Streep joked later, “but no!” In fact, late for a fitting with Isaac Mizrahi after the event – Mr. Mizrahi had designed the gown she would wear to the American Film Institute tribute just two weeks later – she hailed a cab outside the Marriott only to be cut off by a woman claiming she’d been there first. “But it’s Meryl Streep Day!” Ms. Streep complained. The woman relented, shared the ride and paid the fare. Many stars say they despise the limelight, then promptly glow in it. But Ms. Streep is not built that way. She gives as few interviews as possible. Before the luncheon, reporters seemed to be cramming years’ worth of questions into one lightning round: “Who’s your favorite young actress?” “Do you have anything left on your wish list?” “What’s it like working with Denzel?” – this last because Jonathan Demme’s remake of “The Manchurian Candidate,” starring Denzel Washington, Liev Schreiber and (in a smaller role) Ms. Streep herself, was soon to be released. Ms. Streep found it difficult to handle even these softballs, the kind most red-carpet veterans would bat away with ease. She tried at first to answer everything seriously, gracefully, but gradually gave up and shook her head. When asked what it felt like to be honored by New Dramatists, Ms. Streep answered, rather too honestly, “If I don’t get another award in my life, I’ll go to my grave happy.”

In recent years, however, Ms. Streep has begun to accept one prerogative of her position: having the press – and thus the public – listen to what she wants to say. Despite her distaste for celebrity-centric media, despite the possibility of seeming like another Hollywood liberal dilettante, Ms. Streep has re-emerged as a highly political animal, relentlessly exploiting the recent calendarful of Meryl Streep Days as an opportunity to bash the Bush administration. At the Golden Globes in January, accepting an award for her work in “Angels in America” on HBO, she attacked Mr. Bush’s position on gay marriage; backstage afterward, when asked what the biggest problem facing America was, she said, “It has three initials.” Toning it down for the New Dramatists luncheon in May, she merely took a swipe at Mr. Bush’s famous word-mangling. But at the Radio City Music Hall fund-raiser for John Kerry earlier this month she really pulled out the rhetorical stops. “During Shock and Awe I wondered which of the megaton bombs Jesus, our president’s personal savior, would have personally dropped on the sleeping families of Baghdad,” she said. “I wondered, ‘Does Jesus understand collateral damage?’ ” And for an actress so long mesmerized by the sufferings of the individual soul, her role in “The Manchurian Candidate,” which opens nationwide on Friday, suggests the further emergence of a new set of concerns. As a conservative politician whose ambition for her son knows no bounds – not even those of paranoid science fiction – she looks like Senator Clinton but behaves like Madame Mao. Her character doesn’t suffer at all (except at the end); she barrels through meetings, smacks down the opposition, cracks her ice, gets done what must be done. In the process, Ms. Streep unhesitatingly steals the movie. It’s hard to remember that the story is about an evil multinational corporation implanting a mind-control chip in a vice-presidential candidate, not about that candidate’s mother. “But you see in my mind I am the main figure in the movie!” she said, meaning her character. “And so many questions are interesting about a woman like that, a woman in power and how she’s regarded. I’m fascinated by people like Liddy Dole and Margaret Thatcher and Madeleine Albright. I just looked at all those people, the ones who make things happen. Karen Hughes and Peggy Noonan. Their certainty. Unshakable. Ann Coulter! People like that work all their lives to achieve these positions where they can move world events – and then they can’t control them. That’s my character. They get into a place where they control nothing. Because they never learn that the tangent is the thing that really controls events.”

Although she studied tapes in order to nail their mannerisms and attitudes, Ms. Streep already knew these women. She was, until recently, an “insane” news hound. Her day would begin with Imus and C-Span, proceed through “Morning Edition” and Leonard Lopate, end with a compulsive clicking around the TV dials and a spin around the Web in the evening, with a little work (not to mention family life – she has been married to the sculptor Don Gummer since 1978 and has four children) squeezed somewhere in between. “But even while I was working and reading and doing other things, I had that noise in my ear,” she said. “I have my antennae out, what can I say? I’m hyperalert to all signals. When we picked our house in Connecticut – this was after I played Karen Silkwood – it was because it was 90 miles from any nuclear facility. We actually drew the circles on a map. When I moved out of New York it was because of Ramzi Yousef saying `I’m going to come back to the World Trade Center.’ And I think I’m the only human being who believed him. “You see, I’m enormously suggestible. That’s my job as an actor. But even besides that, my boundaries are not so clear, the outline is not so strong. I sort of bleed out into whomever I’m talking to. My children always make fun of me on the phone; they can tell, even if I’ve just been talking to Information, they go, `It was a Haitian operator, right?’ So there’s that. But I’m also smart and I read. I pay attention. And when I saw the videotape of those guys riding through the Holland Tunnel” – here she adopts a disconcertingly realistic Arab accent – ” `We have big thing for you, America,’ we felt, you know, time to go. And so we lived very happily in the country for a while, and then everybody was graduating from various schools and I did a play in the park” – it was “The Seagull” in Central Park in 2001, opposite Kevin Kline – “and had a wonderful time and thought, `Well, maybe I’ll do plays and live in the city.’ So we moved back in. Sept. 9. Because I wasn’t worried anymore.” Ms. Streep did not dwell on the obvious. She merely said, “You see, I’m not paranoid. I’m right, you know,” and laughed.

Taking things seriously is virtually Ms. Streep’s trademark, partly in response to the presumed frivolity of acting, which in college she thought of as silly – mere “playing.” (To avoid that stigma, she almost chose a career in costume design.) “I’m from New Jersey,” she explained. “It seemed highfalutin for an actor to say `I’m an artist.’ ” She got over that resistance; but taking her seriousness into the political realm has been an uncomfortable undertaking. It’s hard to insist on privacy when you make policy pronouncements, and one of the ways she has tried to deal with tension she feels between her roles as a celebrity and an involved citizen is to keep the connection between the two a one-way street. She wants to influence the public, but at the same time keep the public at bay. Voicing her more recent political stances, however, has meant breaching the privacy she had created for herself and her family, exposing the protected ground of her relatively placid domesticity to the ruckus of the outer world. She has done so, in small ways, before: on discrete crusades against domestic violence or Hudson River pollution or nuclear power, or against the apple pesticide Alar (a fight which was based, she later learned, on shaky science). Through it all she remained, as she once told a reporter, “more like Julia Roberts than Erin Brockovich.” But now, as her children become adults (only the youngest, just 13, still lives at home) there is less within the domestic bubble to protect and, she obviously feels, much more outside it to fight. “What pushed me over the edge?” she asked. “Name a topic. Everything pushed me over the edge! The quiet dismantling of environmental regulations. The phoniness of No Child Left Behind. Everybody should be getting up and making a big fat noise. Yes, of course, I always question why anyone would listen to an actor. But it’s not your profession so much that defines you as your personhood. I listen to all kinds of people whose qualifications to opine on anything are that they have a radio show or a degree in art history. Our most famous president of late was an actor. You don’t jettison your citizenship just because you’re famous.”

Still, deploying her stardom in this way is tricky for someone who finds the whole notion of stardom lunatic and distasteful. She knows perfectly well how some people will take it – sure enough, Internet chat rooms had a field day with the Radio City comments – and also knows what this sort of thing can do to a career. (Her first movie co-star was Jane Fonda.) She’s aware of the awful clichés evoked by an actress taking on a cause. But Ms. Streep is no starlet showing up at a benefit for a picturesque disease. For one thing, the gravitas of all the heavy roles she’s played still hangs on her persona like a mantle of moral authority. For another, she does her homework, turning her familiar old skills – the meticulous research, unwavering concentration and deep listening – to a larger idea of her job in life. Whether these considerations will be enough to protect her from the resentment of fans who prefer her to stick to the script, or from a lifelong tendency to overdo things, remains to be seen. In any case, she’s not giving up her day job. “I still love acting,” she said. “I love it. Love it. Love it, love it, love it.” She deployed each repetition of the phrase on a different fluty pitch. “It still feels like the wind in my hair.” We were sitting in a hotel suite a month after the Marriott luncheon, Ms. Streep with her back to the bright windows so that she was almost in silhouette. Her features were multi-tasking – brows lifting, cheeks flushing, eyes instantly clouding and clearing. In the midst of one thought she was already glancing as if down a hallway toward another, slamming unproductive conversational doors and opening others a crack; her hands kept trying to help somehow, but seemed to operate on their own recognizance. At one point they proceeded to top off her coffee cup, unfortunately from the teapot. She cackled raucously. “See, that’s why the glasses are so necessary at this point,” she said, picking up the pair she’d left at her side but not putting them on. “Ah, vanity,” she sighed.

At 55, her vision may be less acute, her features softer, but Ms. Streep’s image has barely budged since she was beatified on the evidence of her first film, “Julia,” in 1977, when she was 28 and fresh out of Yale Drama School. Canonized by 1982 (at which point she’d already made “The Deer Hunter,” “Manhattan,” “Kramer vs. Kramer,” “The French Lieutenant’s Woman” and “Sophie’s Choice”), Ms. Streep has in the subsequent 22 years made 25 major films, while Ms. Fonda, Jessica Lange, Marsha Mason, Debra Winger, Sissy Spacek, Sally Field and the rest of her cohort have drifted to the margins of the industry. Partly she survived on her chameleon skills. “However you first appear in the public mind,” she said, “that’s the image you have to undermine right away. Certainly when I was younger my looks were very important to my success. What made me emerge, I’m sure, was all that hair and, you know, the perfect skin and all those things. Who I really was, was much more Byzantine and many, many, many faceted.” The Byzantine has certainly emerged over the years. At the New Dramatists luncheon, she did one of her ingratiating dithery-ditzy routines, abjuring glamour completely. While the program featured the famous Hirschfeld caricature of Ms. Streep circa 1980, looking sleek and witchy, with a pointy chin and long, Nina-filled hair, the real Ms. Streep – in a black frock coat and pants, with a polka-dot blouse tied sailor-style at the waist, her hair cut in a simple Hillaryesque bob – looked like a distracted magazine editor. She had on little oval purple-tinted glasses and carried a red Totes umbrella, which during the photos, in her only concession to glamour, she handed to Tony Kushner, who looked happy to oblige.

So she doesn’t do regal, she doesn’t do glitzy, she doesn’t do sexy, but even the “Streepgoddess” (as Mr. Kushner calls her) is subject to the familiar and merciless rules of Hollywood: the cellulite ceiling through which no middle-aged woman can pass without a plastic surgeon. Though she has not surrendered herself to them – she’s never had her wayward nose fixed, she’s trim but not skinny and the lines around her eyes are perfectly visible – she is limited, like all other actresses, by the parts available and the material being filmed. William Styron, despite her entreaties, did not write her another “Sophie’s Choice.” Perhaps because she seemed to have tackled every serious dramatic challenge (and every obscure accent) in the first decade of her fame, no one knew quite what to do with her in the next, which was framed by the mortifying “She-Devil” in 1989 and the treacly “Music of the Heart” 10 years later. She never gave less than an intelligent performance, and often popped out of mediocre films with unexpected gifts (such as her belty rendition of “I’m Checkin’ Out” in “Postcards From the Edge”), but for a while it seemed as if she was twisting rather brilliantly in the wind. This may be simply because she made some bad choices, or because she had priced herself out of the best parts, which for women in their 40’s were mostly to be found not in the kind of top-dollar Hollywood movies she favored but in the grungier precincts of independent film. But then, at the beginning of her third decade on screen, the same strategy, or lack of it, that had produced some real duds (and, with “The Bridges of Madison County,” a guilty-pleasure hit) suddenly paid off with “Adaptation,” “The Hours” and “Angels in America” – three riveting performances in three different styles in a period of 12 months. It’s not that she had abandoned the huge seriousness of her early movies – though she is much more likely, these days, to be seen in supporting and comic roles. It’s that she now seemed to be on a quest to light up ever smaller and odder corners of humanity. It should barely come as a surprise that in her next film (“Lemony Snicket’s A Series of Unfortunate Events,” due out this winter) she plays a gothic crone, or that the upcoming projects she’s committed herself to (a fact-based Chinese drama, a Sandra Bullock comedy and an English remake of a French film about an abused prostitute) are so varied; for several years she has been choosing roles – spinsters, monsters, third bananas, frumps, even a rabbi in Mr. Kushner’s “Angels in America” – as if daring moviegoers not to categorize or fetishize her. Or even, as in the case of the rabbi, to recognize her. So our Greatest Leading Lady has remade herself as a character actress – and a character. By doing so, she’s found a way to go on making films until she physically can’t; she also promises a return to the stage, and the rich roles it offers a middle-aged woman, once her 13-year-old is out of the house, in another few years. (Filming rarely took her away from her family for more than a few weeks at a time, she said, but a play would have rendered her an absentee mother for months.) One thing she won’t be doing, she said, is inundating herself with C-Span and Imus; no more news hounding and midnight wonkery. “I’ve cut myself off because eventually it strafes your sense of well being and ability to make jokes,” she said. “Which are important. And maybe it had something to do with weaning myself from ‘Manchurian,’ too.”

Still, the movie, with its implicit critique of the Bush administration, is likely to kick up a storm, and then there’s the matter of the election itself. With her exquisite antennae and maternal fervor – she has played mothers convincingly from the very beginning of her career – it’s hard to believe that Ms. Streep will really manage to resist the lure of politics, which after all stems from the same sort of expressive need that fuels her acting. A woman who moves closer to ground zero after Sept. 11 – she recently put her Greenwich Village townhouse on the market and bought a loft in TriBeCa – is not exactly running away from the world. “We will not be displaced,” she explained, with theatrical emphasis. Not that she’s running toward the world, either. As she sees it, she’s just responding to the circumstances she finds herself in. “I don’t have any special role to play,” she said, instinctively reverting to acting terms. “All I have is this big throbbing conscience.”