One of the greatest accomplishments of the first several months of Barack Obama's presidency has been the near-total marginalization of the Republican right. Rather than developing a coherent alternative to the president's agenda, the right has descended to frantic, tone-deaf cries of "socialism," has allowed some of the least popular figures in public life--Dick Cheney, Newt Gingrich--to be their spokespeople, and most recently, seems to have staked everything on a defense of the previous administration's most disgraceful (and, incidentally, unpopular) conduct.

Even moderate Republicans, such as Rep. Mark Kirk of Illinois, seem to have waded deep into the crazy swamp. Kirk, a Senate hopeful who once bragged to me that he had worked for George Soros on a humanitarian project in the Balkans, recently denounced a proposal to increase a state tax by 1.5 percentage points: "The people of Illinois are ready to shoot anyone who is going to raise taxes by that degree." Mistaking the small rallies called "tea parties" for actual backlash, one Republican bragged to Politico that opposing a yet-unnamed Supreme Court nominee would bring them back to power, "just as we helped ourselves by opposing the [economic] stimulus."

But as the right has taken its rhetoric and self-delusion to 11, its popularity, credibility, and congressional power have sunk to unprecedented lows. (There have been fewer Republicans in Congress before, but that was back when Southern conservatives were still Democrats.)

None of this was inevitable. Self-marginalizing insanity is not an inherent Republican trait. When historians are finished writing countless books in awe of the rise of the right, they will turn to its abrupt decline and find it one of the most puzzling questions in political history.

One answer--and the reason I called it an "accomplishment"--is that Obama's approach to partisanship helped marginalize the right. Often seen as a naive assumption of bipartisan cooperation, Obama's invitation to Republicans to join in governing and offer their best ideas was instead a brilliant calling out of a faction that was prepared only to oppose. (Hence the right's gleeful anticipation of a fight over a Supreme Court nomination, which is a pure yes-no choice.)

Going a few years further back, the explanation for Republican decline may lie in the strategy of governing adopted when the right was in power. With a narrow majority based in the white South, and with demographic trends running against them, the Republicans pulled out all the stops and tried to wring every possible advantage from the moment, a strategy exemplified by former House Speaker Dennis Hastert's "majority of a majority" rule, under which he would refuse to bring to the floor any legislation that wasn't supported by a majority of Republicans, blocking many bipartisan coalitions. Trained to govern in this desperate, high-stakes mode, the Republicans have no ability to step back into the role of a constructive minority that actually tries to collaborate in governing. They governed more like a high-flying hedge fund than an investor with a long view. In opposition, they take the same approach.

A third explanation is suggested by the obituaries in early May for former Rep. Jack Kemp. Kemp was in many ways a disappointing, incoherent, manic figure who, like Newt Gingrich, mistook slogans for ideas, but he very much represented the path not taken for the Republican right. That path was one of racially and culturally inclusive conservatism, based on an ideal of broadly shared economic opportunity and security.

Given the cultural conservatism of many African American and Hispanic voters, and the aspirational values of most families, conservatives could have had a chance to construct a durable coalition around Kemp's values. If Republicans could get even a third of the African American vote and retain the 40 percent of Hispanic votes they reached in 2004, the entire map of American politics would be different. It's likely that a more racially inclusive politics would be more appealing to younger voters as well. But Republicans didn't do it, and now it's too late.

Why did the right not take the path Kemp offered? Perhaps the party's mostly Southern leaders just didn't get it or didn't want a racially inclusive party. Maybe they would have lost more white votes in the process. Or perhaps the whole idea was doomed by its incoherence, and what Kemp really had to offer was liberalism combined with massive tax cuts.

We'll never know, because the right chose a different path. Conservatives, or at least the Republican Party, will return to power, but not until they show some curiosity about their mistakes.