CBS News reported on Thursday: “Senator Amy Klobuchar, Democrat of Minnesota, has been asked by Joe Biden to undergo a formal vetting to be considered as his vice presidential running mate, one of several potential contenders now being scrutinized by his aides ahead of a final decision, according to people familiar with the moves.” This should surprise no one. It would be extraordinary if he did not vet an experienced senator from the Midwest who ran for president and is ideologically compatible with Biden.

The news unleashed breathless speculation that Klobuchar will be the pick, but, of course, the report says no such thing. As we hear about vice presidential vetting, we should keep in mind some simple rules of vetting.

First, a presidential nominee has to vet several people. If something troubling comes up about one or more possible picks, the nominee has to have viable alternatives.

Second, there is only one person who might know which contender he wants, and former vice president Joe Biden is not telling. In his own mind, he may have narrowed it down to a few people as he awaits the results of the vetting process. Speculation will run rampant; there will be much talk about a contender’s “stock” rising or falling. Don’t buy it. Anyone who says he or she knows who Biden will pick doesn’t really know.

Third, vetting is not a simple matter. As the CBS report indicates, “If a potential contender consents, she should be poised to undergo a rigorous multi-week review of her public and private life and work by a hand-picked group of Biden confidantes, who will review tax returns, public speeches, voting records, personal relationships and potentially scandalous details from her past.” A contender knows if she is being vetted because a good deal of the information will come from her. If someone says she doesn’t know whether she is under consideration, she isn’t leveling with you. If you are, you know; if you aren’t, you know.

Fourth, surprise picks (e.g., Dan Quayle, Sarah Palin) do not tend to work out. A nominee is not likely to win because of a running mate, but a running mate could lose votes. Given the stakes and Biden’s own experience as vice president, I would not look for an “out-of-the-box” choice. If you haven’t heard a name mentioned seriously, that person almost certainly won’t get the nod.

There is something to the adage that the only two times a VP pick matters are on the day of the announcement and on the day of the VP debate (if there is one, which, in this case, there may not be). As much as Biden wants a governing partner with whom he is simpatico, any contender who is not fully capable of performing on those two occasions is a high-risk choice. Biden, I strongly suspect, is not a risk-taker in this regard.

Finally, the vetting is also about the spouse. A scandal or personal liability of a spouse can be troubling, as Walter Mondale’s campaign found out the hard way in 1984 when questions about Geraldine A. Ferraro’s husband’s finances arose (after insufficient vetting of him). Since the spouse in this case may be a lawyer (e.g., John Bessler, Doug Emhoff, Bruce Mann), a whole list of questions about past clients and future intentions about his law practice may come into play. This is not a quick or painless process.

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