Sometimes the Internet bloggers get ahead of the mainstream press and sometimes they indulge in wishful conspiratorial theories. We’re not sure which they did in calling to public attention a rectangular bulge in President Bush’s suit jacket in the first presidential debate. But the Bush campaign would do well to come up with a single explanation to answer them.

When The New York Times and other news organizations finally caught up recently, they asked the White House for an explanation. There followed a series of statements from the campaign, each one doubtful or discredited.

First, there was no bulge, although it appeared in televised pictures of the president’s back. Second, someone had manipulated the picture to fake the bulge, but it showed up in the original pictures. Third, a spokeswoman said it was most likely a rumpling or a wrinkle, but that didn’t account for the rectangular shape. Then the president’s tailor said it was a pucker along the jacket’s back seam, accentuated when the president crossed his arms and leaned forward. The New Yorker’s recent profile of the president’s tailor, Georges de Paris, made it clear that the man who has been tailor to every president since Lyndon Johnson was unlikely to leave oddly shaped puckers in a jacket. Finally, the spokeswoman tried to end speculation by declaring, “There was nothing under his suit jacket.”

Maybe. But the mysterious bulge is a perfect case for application of a rule of logic called Occam’s Razor. William of Occam, a 14th century English logician and Franciscan friar, advised that whenever there are multiple explanations for a phenomenon it is best to take the simplest one.

The bloggers already have made one simple leap: Mr. Bush was wired when he went into that first debate. (They suggest as evidence the clue that the president suddenly said, “Let me finish,” when nobody in sight was stopping him.) But there’s no further evidence for this and wouldn’t some connection to an earpiece also have been visible if this was the case? There’s no reason to speculate; there is good reason for the campaign to look at the photos again and provide an explanation.

Judging from the president’s performance in the first debate, whatever the shape turns out to be wasn’t much of a help to his performance.