The following is a JPost.com exclusive blogHistorians should be careful not to pronounce a contest over till it's over, so I will not join the pundit pile-on eulogizing Hillary Clinton's campaign. However, the conventional wisdom about this fight's impact may be wrong. Hillary Clinton's relentless push for the nomination may have strengthened Barack Obama, not weakened him.The lengthy American presidential campaign does not proceed in straight lines but in waves, with dramatic ups and downs. This is not necessarily a natural phenomenon but usually a media-driven mania. Reporters frequently build up candidates, then knock them down or build them up after knocking them down.Skilled - and lucky - candidates can win by having the inevitable downturns far enough away from Election Day not to hurt. John McCain, for example, benefited from bottoming out last summer and fall, long before Republicans started choosing their nominee. He was able to come on strong in the winter when it counted.Moreover, Democratic primary voters are prone to buyers' remorse. The modern politician who has most benefited from this tendency is that old warhorse, Jerry Brown. Brown, the current Attorney General of California and former wunderkind Governor of the same state, enjoyed late surges in two presidential campaigns.Each time, Brown eventually lost but only after giving a relatively inexperienced contender enough of a scare so that the come-from-nowhere Democrat became the eventual winner in the general election campaign. In 1976, Democrats turned to Brown when they started wondering about Jimmy Carter; sixteen years later, Brown's campaign attracted votes in the spring from Bill Clinton, as he marched toward the nomination.In fact, thanks to Brown, the rise of Ross Perot, and his own scandal-laden past, Bill Clinton faced a major crisis in the late spring of 1992. His advisers launched the grandiosely named "Manhattan Project," a secret initiative to analyze Clinton's weaknesses and figure out the secret ingredients needed to propel him to victory. Given Clinton's victories in 1992 and 1996, people tend to forget how unpopular he was, even after he had clinched the nomination.When his advisers presented him with data detailing how little Americans trusted him, Clinton exploded: "So far as I'm concerned, we're at zero," the Arkansas governor fumed. "We're a negative. We're off the screen. We don't exist in the national consciousness. We might as well have been like any member of Congress and kissed every ass in the Democratic Party. I don't think you can minimize how horrible I feel, having worked all my life to stand for things, having busted my butt for seven months and the American people don't know crap about it after I poured $10 million worth of information into their heads."Ultimately, this crisis helped Clinton and his advisors recast the campaign's message - and take the White House. Candidates need to be tested. One of the unlucky breaks Hillary Clinton experienced was that she - and her staffers - floated to re-election during the 2006 New York Senate race. As a result, they entered the 2008 presidential campaign soft, relatively un-tested, and far too self-assured.Similarly, had Barack Obama seized the nomination after his meteoric rise in February, his campaign would have been an overinflated balloon, soaring high but easily popped. Most notably, given how deep Obama's ties are to the ministerial hate-monger Jeremiah Wright, it was far better for that embarrassment to be aired this spring than next fall. Obama has had time to figure out how to deal with this and - after repeated hesitations - make the necessary break.Timing counts. Just as the Clinton campaign probably could have derailed the entire Obama phenomenama had Hillary's people done their homework and exposed the wrongheaded Wright in January, if Obama is lucky, by the fall Americans will be more concerned with "the economy, stupid," than with Obama's passivity in the face of Wright' repeated affront to American values.Hillary Clinton's tough fight against Barack Obama has toughened Obama. The Democratic primary campaign has focused Obama on the need to hone a message that reaches working class whites. The early exposure to the Wright controversy may have inoculated the public against further outbreaks of this particular affliction. If - and I make no predictions - Barack Obama ends up winning the White House, he just may have to thank Hillary Clinton for her unintended help along the way.