I asked Joel Goldstein of St. Louis University (author of "The Modern American Vice Presidency: The Transformation of a Political Institution") who has become my go-to guy on matters vice presidential for his reaction to John McCain's veep pick. Here's his reply:

"I'm stunned by the choice of Governor Sarah Palin just as I would have been surprised had Senator Obama picked Governor Kaine or Senator McCain picked Governor Crist. I think that a threshold choice for a vice-presidential selection is that the candidate has to be presidential.

"We have not had a vice-presidential candidate with so little relevant experience since Spiro T. Agnew. It is doubtful that any or many would have ranked her as one of the Republicans they would most like to be a heartbeat away. Years of experience alone is not, of course, the only measure of whether someone is presidential timber and perhaps Governor Palin, like Lincoln or FDR, has gifts well beyond her experience. The most charitable view of Senator McCain's pick is that, having met with her (which I assume he has done), he has decided that she is presidential. If that is his conclusion and her performance vindicates his faith it may prove a good pick.

"On the other hand, there are disturbing things about the choice. Especially given Senator McCain's age and health history, one might question his judgment in putting someone with so little experience a heartbeat away. Senator Obama has had twice the time in the Senate as she has had as governor and has been tested in the most strenuous presidential nomination battle in our history against the presumptive nominee among others.

"It should be hard for even a Republican partisan to credit claims that Senator Obama is not ready when Senator McCain chose someone with far less experience on a quantitative or qualitative basis. If the choice reflects a gamble that Senator Clinton's unhappy supporters will favor Senator McCain because of Governor Palin's gender it indicates a rather cynical view of their decision-making process. That clearly seems to be part of the strategy, witness her praise at her rollout for Representative Geraldine Ferraro and Senator Clinton, not two of the traditional heroines of the Republican Party.

"Did the choice of Governor Palin instead of someone like Secretary Ridge represent a cave to the right wing?

"I think Senator McCain was in a tough spot. He needed to convince the base, especially the social conservatives, that he was one of them. He also needed to protect, perhaps reinforce, his maverick image. Choosing Governor Palin did both (whereas Governor Pawlenty would have helped with the base but not with maverick). In doing so, however, Senator McCain ran the risk that if people can't see Governor Palin sitting in the Oval Office they will discredit his judgment and see him as having made a crass political move which runs counter to the image he seeks to project of doing the right thing whatever the consequences.

"Unless Senator McCain has determined that she really is the second coming of Lincoln, the choice might lead one to infer that he thinks he has a very uphill race. The choice is an effort to reshuffle the deck which suggests that the person who made it sees the status quo as unlikely to produce victory.

"Governor Palin will present some tactical problems for Senator Biden in the debate. The expectations game will be all in her favor. With a low bar, she could lose the debate and still win.

"On the other hand, the late timing of the choice poses some real problems for her. Having dealt with the Alaska problems and the Alaska media and with that of the small town she led, she will now have to address international and national issues before the national media, and with no spring training. Not an easy position to be in."

What think?