That sound you hear: the starting gun on the general election.

Flying to Riyadh, Saudi Arabia aboard Air Force One earlier today, George W. Bush adviser Ed Gillespie took the time to answer a few questions from the White House press corps. The topic of discussion? The president’s speech yesterday to Israel’s parliament in which he accused “some” people “seem[ing] to believe we should negotiate with terrorists and radicals,” comparing them to those who “appeased” Adolf Hitler during World War II. Asked if the Administration “may or may not have anticipated the reaction that ultimately occurred, where people interpreted this as a reference to Barack Obama,” Gillespie pleaded ignorance. “I’m surprised and curious,” he said. Gillespie couldn’t even guess why Bush’s remark was interpreted as an attack. “I’m not a sociologist,” he quipped.

Fortunately for Gillespie, sociology doesn’t explain it. Politics does.

As we wrote yesterday, it doesn’t really matter whether Bush meant to bash Obama or whether, as Gillespie put it, “the speech was really designed to talk about the President’s policies, the policies of the United States.” (Although White House aides privately told CNN and NBC that Bush’s remarks did, in fact, refer to the Illinois Democrat, and it’s hard to imagine that his staff of political pros was caught completely unawares.) What matters is the political repercussions–who’s helped and who’s hurt. Clearly, Democrats saw Dubya’s disquisition as a golden opportunity to frame this race as Obama versus the most unpopular president in modern history–and were happy to leap to a conclusion (“some”=Obama) that was politically convenient, if not necessarily indisputable. Joe Biden called the comments “bulls**t”; “Does the president have no shame?” asked Rahm Emanuel. Linking this exquisitely histrionic outrage to Obama’s frequent attempts to portray McCain as “four more years” of Bush, I predicted that the candidate himself would soon weigh in. “Now that Bush has entered the ring,” I wrote, “Obama can finally fight the opponent he’s been itching to fight all along”: John W. McBush.

Let the games begin. Appearing this afternoon in Watertown, S.D., Obama used his first speech since Wednesday to accuse Bush and McCain of “hypocrisy, fear-peddling, and fear-mongering.” Bush’s remarks represent “exactly the kind of appalling attack that’s divided our country and that alienates us from the world,” said Obama. “And that’s why we need change in Washington.” Quickly pivoting to his Republican rival, the near-nominee then contrasted McCain’s calls for post-partisan governance with his reaction to Bush’s remarks. “John McCain gave a speech in the morning where he talked about the need for civility in our politics,” he said. “Not an hour later, he turned around and embraced George Bush’s attacks on Democrats. He jumped on a call with a bunch of bloggers and said that I wasn’t fit to protect this nation that I love.” And yet McCain, said Obama, “still hasn’t spelled out one substantial way that he’d be different from George Bush when it comes to foreign policy.” Judging by the way the Watertown crowd cheered every word–or, every word but “Bush”–we haven’t heard the last of these lines.

Is Obama’s onslaught fair? McCain hasn’t called for “100 years of war,” as Obama likes to put it. Despite the heated rhetoric, their plans for the of future Iraq aren’t that far apart. (“McCain has bowed to the political reality that American impatience with the war is growing,” wrote the Los Angeles Times this morning, “and Obama to the fact that a poorly executed exit would risk damage to other vital U.S. interests.”) And whether or not the U.S. president should agree to unconditional talks with, say, Mahmoud Ahmadinejad of Iran is a worthy subject of debate, as McCain has repeatedly (and rightly) said. But fair is irrelevant here. “It was remarkable to see Barack Obama’s hysterical diatribe in response to a speech in which his name wasn’t even mentioned,” said McCain spokesman Tucker Bounds this afternoon. But the truth is, it’s no more remarkable than McCain characterizing Obama as Hamas’ candidate of choice, or saying that he’s “singularly lacking specifics” when it’s the other way around. This isn’t sociology; it’s politics. When McCain stretches Bush’s non-specific remarks to launch a specific attack on Obama–“it shows his naivete and inexperience,” he said–he’s trying to score political points (with Jewish voters in Florida, perhaps); when Obama stretches Bush’s non-specific remarks to call McCain “more of the same,” he’s trying to score points, too. This is the big show now. We’ll know in November who’s won.