Earlier this week, former Minnesota governor Tim Pawlenty, one of the more plausible possible GOP presidential nominees, rebunked birtherism just as Donald Trump and Fox News were eagerly indulging in a crank renaissance.

But if you think the birthers, the "creeping sharia" crowd, and the New Black Panther Party obsession are all going to fade away sometime soon, you've got another thing coming, and not just because, as Jonathan Bernstein noted yesterday, birtherism allows Republicans to pander to a segment of their base whose policy views are unpopular. National Journal's Ron Brownstein explains that, just as an Obama victory is going to depend on strong minority turnout, Republicans will need to "win an implausibly high percentage of whites to prevail."

Unless Democrats regain some of the support they lost in 2010, Obama has no guarantee of matching his 2008 share of the white vote, especially in metal-bending states such as Ohio and Indiana, where voters without a college education dominate the white population. "You have a situation where the bleeding can be so severe that it can overwhelm the changes that are positive," says Ruy Teixeira, an electoral and demographic analyst at the liberal Center for American Progress.

But in more racially diverse states, the National Journal's analysis suggests, Republicans may need to win an implausibly high percentage of whites to prevail, unless they can also reduce Obama's advantage among minorities. "I think Republicans have long felt and known we need to do better in minority communities," says GOP consultant Mike DuHaime, the field director for John McCain's 2008 presidential campaign. Pursuing that goal is likely to acquire more urgency as both parties digest the implications of the 2010 Census.

The Republican Party had a choice after 2008. They could continue to rely on a dwindling but still decisive share of the white vote to prevail, or they could try to bring more minorities into the party. While I'm not entirely sure how much of the decision was made by party leaders and how much is merely the unprecedented influence of Fox News, but whether it's pseudo scandals of the past two years, from birtherism to the NBPP case, the GOP's nationwide rush to ban sharia and institute draconian immigration laws, or characterizing nearly every administration policy as reparations,  the conservative fixations of Obama's first term indicate that the GOP will end up relying at least in part on inflaming white racial resentment to close the gap. If Obama can't mobilize as many minority voters as last time, he'll have to make up the difference by picking up more white votes in those Rust-Belt swing states — giving the GOP even more reason to make Obama unpalatable to them. What that means though, is that Obama can hardly afford to adopt the kind of hardball identity politics available to his opponents.

The personal qualities of whoever gets the Republican nomination probably won't matter. While McCain, to the chagrin of many Republican strategists, notably avoided dragging the views of Obama's former pastor, Jeremiah Wright, into the contest last time around, the next Republican nominee won't have much of a choice, because the GOP has spent most of the past two years alienating minority constituencies.

Ultimately, the state of the economy is still the most important factor in what happens in 2012. But judging by the past two years and Brownstein's analysis, things are still going to get pretty ugly.