"There is only one president at a time" has become Barack Obama’s mollifying refrain for the lame-duck interregnum. But on movie screens, an alternative president has always been close at hand, and during transition periods, Hollywood has done its bit to pave (or point) the way for the gestalt with a virtual leader or two. The historic challenges awaiting this president-elect—economic depression, war, postpartisan healing—have all been faced by fictional heads of state, usually bearing amusingly “presidential” Anglo-Saxon names.

Take President Judson Hammond, for example, who hails from an era frequently invoked by Obama in recent months. In Gregory La Cava’s over-the-top Gabriel Over the White House (1933), Hammond (Walter Huston) takes office after the Great Depression has left millions unemployed. But the new head of state is a gladhanding bachelor more concerned with repaying supporters and retaining a secretary/mistress than with policy. In one scene, he crawls around his office playing with his nephew, while an impassioned radio address by a populist leader blares in the background.

As in other presidential movies, Gabriel dramatizes our experience of changed leadership through a single executive’s transformation. The kickstart toward electoral wish fulfillment is wonderfully strange. Hammond, the first president to drive his own car, crashes while speeding and enters a coma; he awakes under the aegis of an unseen angel (whose presence is marked by a breeze through the curtains and a shift in the lighting on Huston’s face). Then, presto! Instant FDR. With a sense of mission and leadership, an invigorated Hammond initiates New Deal-style work programs and pays a respectful visit to protesters—the latter action in pointed contrast to President Hoover, who set the Army on jobless veterans (in the event known as the Bonus March).

Gabriel envisioned a populace receptive to major reform, but presidential action is always shadowed by the danger of overreaching, and Hammond is no different: he eventually adjourns Congress in the name of expediency. That might be a step too far even for rabid supporters of our president-elect, in the wake of the Bush administration’s abuses of executive powers. But Gabriel premiered shortly after FDR spoke of "broad executive power" in his inauguration speech—to great applause. (The inauguration parade in Gabriel even appropriates newsreel footage from FDR’s actual procession.) In tough times, Hammond gets away with a lot: belligerent Prohibition gangsters are convicted by a military tribunal and shot against the backdrop of the Statue of Liberty. As for foreign policy, Hammond convenes European leaders on a yacht and demands payment of World War I debts; he destroys two of his own battleships to make his point.

While this kick-ass vision of FDR might differ from Obama's subtler approach, both Hammond and Obama symbolically invoke a restoration to just rule: Hammond signs a new debt agreement with the quill pen Lincoln used for the Emancipation Proclamation, much as our president-elect will be sworn in on the same Bible used for Lincoln's inauguration. Obama's use of Lincoln promises postpartisan reunification and acknowledges his historic accomplishment as the first black president, but he will also be distinguishing himself from the last young Democrat to take office. Kennedy was the touchstone for Bill Clinton, who encouraged the comparison. Oliver Stone's JFK (1991), a pent-up outpouring after the paucity of onscreen presidential material during the Reagan and Bush years, renewed interest in the Kennedy mythos and posited a recasting of history.

But the bland Ivan Reitman comedy Dave (1993) might be the more typical studio response, capturing a change in government and attitude as inoffensively as possible. Following the Prisoner of Zenda template (like 1988's Moon Over Parador), President Bill Mitchell (Kevin Kline) is replaced by a look-alike when he falls into a stroke-induced coma (an occupational danger, apparently) after sex with a secretary (Laura Linney). Despite the hint of Lewinsky, the dismissive, bespectacled Mitchell represents the aloof image of George Bush (there’s even a savings-and-loan scandal that proves crucial to the plot).

The replacement Mitchell, played by friendly temp-agency manager Dave Kovic (Kline), soon thwarts his handlers, and Dave becomes a matter of average-Joe attitude and generic Capra-esque idealism. The prez loosens up, connects with factory workers and an orphan during photo ops, and restores funding to a homeless shelter. Like Bubba '92, he’s a contrast to blue-blood Bush/Mitchell; he wows the still-in-residence first lady (Sigourney Weaver) with his great sub sandwiches. A silly, optimistic welcome to a new presidential age, Dave is essentially the story of a cynical gambit redirected into an opportunity for good works.

Dave also touches on an inconvenient issue of presidential succession—how to deal with your predecessor’s legacy—which is the centerpiece of Robert Aldrich's Twilight's Last Gleaming (1977), released on the heels of an earlier unhappy era. For Dave, the solution is relatively simple: since he is still technically President Mitchell, he admits culpability for the real Mitchell's sins (foreshadowing Clintonian contrition, perhaps), and power ultimately passes to the vice president, an upstanding former shoe salesman (Ben Kingsley, of course). But for President David Stevens in Aldrich’s thriller, the aftermath of the Vietnam War requires a far tougher reckoning, not least because Stevens must make his decisions under threat of nuclear warheads.

The scenario, replete with multiple split screens and some terrific suspense, is pure paranoid pulp—a far cry from the malaise of Nashville (1975), which featured an ever-circling, never-seen presidential candidate—but it strikes a nerve. Disgruntled ex-Air Force man Lawrence Dell (bedheady Burt Lancaster, already a veteran of JFK conspiracy lecture/thriller Executive Action) holds a missile silo hostage. He demands that the president publicly admit the "true" rationale behind the Vietnam War: namely, the doctrine of credibility, by which the war allowed a kind of demonstrative brutality meant to forestall wider, catastrophic conflict with the Soviet Union. President Stevens (Charles Durning), elected partly thanks to party convention deadlock, remains the shocked, principled voice amid his Cabinet of cagey veterans (Joseph Cotten, Melvyn Douglas, et al).

Betrayal is a common theme in Aldrich's brassy output, and this pessimistic, post-Parallax View take on the realpolitik republic is no exception. Taken as a parallel to the incoming Obama administration, which will inherit wars and all manner of legally questionable policy, the conceit has a righteous splendor. But there's an equally relevant naiveté under Aldrich's cynicism; then as now, the secrets are open ones, for the geopolitics behind the Vietnam War were clear by this point. Durning's character embodies a wishful fantasy of emergence from the era of Watergate and Vietnam. Aldrich does get the last cackle, though, with a treacherous, triple-sniper ending that will satisfy connoisseurs of the dirty business of statecraft, but that also probably turned off audiences exhausted by the '70s long before they were over.

Fatigue is what marks the recent 2008 movies featuring presidents, and not just because they were familiar faces. The simplifications of W. and Frost/Nixon presciently induce a mood of, if not quite forgive-and-forget, then fulminate-and-forget. The portrait of Bush in W. is equally astonishing for its selectiveness and for its empathy—not what you’d expect from Stone, who in advance reports seemed to promise an electoral intervention. But it’s hard to stay angry at, or to remember, W. for too long, and likewise Frost/Nixon. Gently mocking Frost adviser James Reston (Sam Rockwell) as an overeager, score-settling lefty, Ron Howard’s movie amounts to a very of-our-moment exultation in cheesy celebrity justice. Misrepresenting Frost’s reputation at the time as laughably fluffy, Howard signals good faith by suggesting no malice of forethought, or much of any thought, on the part of the pompadoured interviewer. By recounting Nixon’s attempted relaunch as a conciliatory piece of pop history, it suggests that a disgraced ex-president is not worth obsessing over—let the post-Bush healing begin. And if the movies can serve as any guide to his replacement, Obama might well need an angel looking over him and a body double just to get everything done.