On desks around the West Wing sit digital clocks counting down the days and hours left in the Bush presidency, reminders to the White House staff to use the time left as effectively as possible. As of 8 a.m. today, those clocks will read 825 days, four hours. But if the elections go the way pollsters and pundits predict, they might as well read 20 days.

At least that would be the end of George W. Bush's presidency as he has known it. If Democrats win one or both houses of Congress on Nov. 7, the result will transform the remainder of Bush's time in office and dramatically shift the balance of power in Washington. Ending a dozen years basically passed in exile, congressional Democrats would have a chance to help steer the nation again -- following a campaign spent mostly assailing Bush's vision rather than detailing their own....

The most salient analogy may be the last time Congress changed hands, after the 1994 elections. President Bill Clinton was left trying to assert that "the Constitution gives me relevance" even as new House Speaker Newt Gingrich (Ga.) and his Republicans seized the initiative. Clinton ultimately recovered through a mixture of confrontation with Republicans, most notably in a government shutdown, and "triangulation" in which he embraced some of their priorities, such as overhauling the welfare system.

The difference is that Clinton's presidency was still young, while Bush is heading into the twilight of his administration -- and is stuck in an unpopular war. But some Republicans think that Bush could play off overreaching Democrats as Clinton did with Gingrich. Or he could pivot to the more bipartisan mode he promised to bring from Texas and seize opportunities for progress in areas such as immigration, where his proposed guest-worker program has been blocked by his own party.