Well, here we are a few days at most before Barack Obama's running-mate announcement, and exactly ten days before McCain's, and nobody much knows what's going to happen.

Taegan Goddard's Political Wire provides an assortment of confident predictions that Obama will choose Kaine, Biden, Reed or Sebelius. Several somebodies are obviously wrong.

And on the Republican side, conservatives went into crisis mode today over reports that the McCain campaign was sounding out GOP officials around the country about the potential repurcussions of a pro-choice Veep (presumably Ridge or Lieberman). Meanwhile, the news that McCain was going to announce his decision in Dayton, Ohio, on August 29, led to speculation that the Bush White House's favorite, Ohioan Rob Portman, was the choice. But Portman indicated less than a month ago that he hadn't been vetted.

We'll all know soon enough, but those who are bored or annoyed with the endless veep speculation should understand that it's provided a public vetting of potential heartbeat-from-the-presidency prospects to complement the private vetting. And that's a good thing.

Until quite recently, this potentially momentous decision was often made casually, and with little or no vetting. Nixon picked Spiro Agnew during the 1968 Republican Convention, mainly because he was one of only two "moderate" candidates not vetoed by Strom Thurmond, whose championship of Nixon in the South headed off a lethal delegate stampede to Ronald Reagan. Nobody knew enough about Agnew to figure out that he was taking sacks of cash from highway contractors, and would continue to do so until the revelation of his corruption forced him to resign. The politically disastrous choice of Tom Eagleton by George McGovern in 1972 was a panicky last-minute decision made after more desirable running-mates had turned down the position, and without the benefit of the minimal vetting that might have exposed his serial drunk-driving charges, if not his electro-shock therapy sessions. (As Hunter Thompson later said: "There were any number of political reporters who could have told them that Tom Eagleton was a man who didn't mind taking thirteen or fourteen tall drinks now and then."). Another highly significant Veep choice, according to most accounts, was a sheer accident: the Kennedys offered the vice-presidential nomination to Lyndon Johnson in 1960 because they assumed LBJ would turn it down.

Hasty and fortuitous running-mate decisions are now a thing of the past. Given the political and meta-political implications of an unwise choice (aside from the more recent examples, cf. John Tyler and Andrew Johnson in the 18th century), enduring endless Veep speculation is a small price to pay for that.