Nearly three months after John McCain named Sarah Palin as his running-mate, what possessed McCain to select her is still a mystery. The McCain-Palin candidacy crashed and burned, but the usual post-mortems have shed no definitive light on McCain’s thinking.

Republicans had a legitimate issue with which to pummel the Democratic ticket:Barack Obama’s thin resume when contrasted with McCain’s lengthy service in Washington. The choice of Palin effectively neutered that argument. Republicans puffed up her resume as best they could but no amount of spin could disguise that there was no there there — no discernible intellectual depth and just 20 months as Alaska’s governor plus service as mayor of backwater Wasilla.

According to Jane Mayer in the New Yorker, “By the time [McCain] announced her as his choice…he had spent less than three hours in her company.” All the more reason for the press to push and prod to fill in the blanks. Mayer’s own thesis in her Oct. 27 piece, “The Insiders: How John McCain came to pick Sarah Palin,” is that a flock of conservative journalists went on a couple of cruises to Alaska where they happened upon Palin, were smitten and created a bandwagon to which tough-customer McCain, who for years had resisted his North Vietnamese captors, succumbed. That is so improbable it just might be true.

Then there is the one about McCain playing the chromosome card. In this version, McCain and his managers figured they could capture all those disappointed women fans of Hillary Clinton by going female. This assumed that Clinton’s women supporters were so besotted by gender they wouldn’t notice that Palin and Clinton were poles apart on almost every issue.

Still another theory is that McCain would burnish his boldness credentials by making a totally unexpected choice. If so, voters would have to be unaware that daring and foolhardy are not synonyms. After Palin read her one-liners well at the Republican convention, it was all downhill. Her lack of depth became so obvious that McCain was trashed in innumerable newspaper endorsement editorials for poor judgment in putting her on the ticket.

The choice was so strange you have wonder about the occult or pseudo-science scenario. After all, Ronald Reagan and his wife were devoted to astrology; one of the couple’s astrologers, Joyce Jillson, claimed to have had a hand in choosing Reagan’s vice-president. According to Jillson, her job was to “review the charts of all vice presidential candidates. I told Reagan that George [H.W.] Bush was the only choice” because Bush “a Gemini was the most compatible with Reagan, an Aquarian.”

Preposterous? No more so than McCain allowing himself to be steamrollered by the right-wing journalists who swooned over Palin.

Exactly how the choice of Palin was made deserves a close look. Too many vice presidents succeeded to the White House for the vice-presidency to be treated as an afterthought. The press has gone on to the fresh news of a new administration but left the unfinished business of just how Palin was put on the ticket. I’ll betcha that unless the press does, there will be more Sarah Palins in our future.