Sandra Bullock is as close as you can get to being America’s Movie Sweetheart.

AP / Gus Ruelas

On Friday, Sandra Bullock rematerializes in The Proposal, after spending about two years off the movie grid (and a few more than that MIA from the romantic-comedy arena). The film, from 27 Dresses director Anne Fletcher, stars Bullock as a pushy Canadian publishing exec who coerces her assistant (Ryan Reynolds) into marriage, so she can stay in the United States.

In the noble traditions of hormones, and Hollywood, they fall in love.

A few things are wrong with this picture. One, no one believes in pushy Canadians. Two, Reynolds is not only prettier than Bullock, he was last seen as a lethal mutant in X-Men Origins: Wolverine, which should disqualify him from further romantic consideration. Third, Bullock is supposed to be America’s Sweetheart, not Canada’s.

She still may be. At 44, Bullock has seen many of her contemporaries — actresses who came to prominence in the ’90s — fall off the face of the Earth. There are exceptions: Michelle Pfeiffer, 51, opens in the Colette-inspired sex-and-romance drama Cheri June 26; she looks and acts fantastic. But no one is shocked by The Proposal, because Sandra Bullock has always spelled durability.

Bullock’s attack on the movie-going consciousness has always been two-pronged, her devastating cuteness matched with a girlish athleticism, her self-deprecating sense of humor playing counterpoint to a sassy tartness. Her dynamic has been about playing the girl next door — and playing the federal agent next door. Few stars of rom-coms have also played futuristic cops (Demolition Man), or FBI agents posing as a Miss America contestant (Miss Congeniality), or author Harper Lee (Infamous, in which Bullock was arguably as good as Catherine Keener in Capote).

In Speed, Speed 2: Cruise Control, Miss Congeniality and Murder by Numbers, Bullock plays the capable, sometimes gun-toting woman with an edge; in Hope Floats, Two Weeks Notice and Divine Secrets of the Ya Ya Sisterhood, she’s more of a cupcake. (There is also a third division of Bullockiana, the less easily categorizable movies like 28 Days, Infamous, Crash and Premonition, which are always described as out of character.) Throughout her career, a combination of earthiness and allure has made her seem singularly genuine in a movie world of big lips, full bosoms and empty heads.

Part of Bullock’s charm also has to do with potential. Although she sports Everywoman looks, there is a moment in Miss Congeniality when the rather humorless, all-business Gracie Hart gets some makeup, a blowout and a slinky dress, and the results are virtually leered at by the camera — until she breaks a heel, and Classic Bullock resurfaces. It’s not that she’s not hot. She just doesn’t play hot (although she has a much-discussed nude scene in The Proposal). But this is why audiences feel they know her. Or are her. And why they recognize the unspoken assertion of her purely American persona that anything can be achieved with perseverance, goodness and perhaps a soupçon of divine intervention, à la Frank Capra.

The role that best exploited all of Bullock’s assets was the 1995 Jon Turteltaub comedy While You Were Sleeping. It’s a movie made of unadulterated schmaltz, but it has irresistible Capra-esque elements of kismet and opportunity. As Lucy, a lonely fare collector on Chicago’s elevated transit line, Bullock fantasizes about a commuter (Peter Gallagher), and one day witnesses him being mugged and pushed onto the tracks. She saves him and then is mistaken by his family for his fiancee.

Lucy is not a femme fatale; on the contrary, she could have achieved Gallagher-hood only by mistake. But we — I mean she — gets to have it both ways, and then, by choice, to be wise: She falls for his less-flashy but more substantial brother (played by another singularly American screen treasure, Bill Pullman). The moral — embodied in the story, and by Bullock — is that goodness will, eventually, reap its own reward.

We love that kind of stuff. We also love performers who can make us feel good about ourselves — or at least not inadequate. There will come a time when Angelina Jolie hits the Hollywood equivalent of the golden years, and it’s hard to imagine audiences rooting for her, not the way we’ll root for Bullock. Which, of course, is really rooting for ourselves.