So, Barack Obama did not pick Gov. Tim Kaine to be his running mate. There were solid reasons to defend a potential choice of Kaine for vice president, but it turns out the arguments made for picking Delaware Sen. Joe Biden were many of the same points for NOT picking Kaine.

Since the Crystal Ball is based in Virginia, we have followed Tim Kaine’s career since it began on the Richmond City Council in 1994.

Picking Kaine would have produced some disadvantages. There are no perfect people, and that goes double for VP picks. So Kaine would have brought heavy pieces of baggage to the Democratic ticket. To those, we point:

1. Lack of Experience Where It Is Most Needed

Other than the possibility of racial leakage at the polls — the chance that many white voters who would otherwise vote Democratic this year will be unable to cast a ballot for an African-American — there is no greater threat to Obama’s victory than his inexperience.

With fewer than four years in Washington as a senator, most of which has been spent running for president, plus a stint in the Illinois State Senate, Obama’s public office resume is undeniably thin. His recent successful Magical Mystery Tour of eight European and Middle Eastern countries notwithstanding, Obama has little or no foreign policy, military, and national security experience.

Overall, Kaine has executive experience as a mayor and governor that perhaps balances Obama’s purely legislative resume. Yet this would be a team whose elective resume is rather skimpy, beginning only in the mid-1990s, with just one truly consequential office each — and not a full term in it for either.

2. Kaine’s Governorship

Few nonpartisan observers in Virginia regard Kaine’s tenure in the Governor’s Office as particularly successful.

Having known every governor since Albertis Harrison (1962-1966) and having studied the records of the dozen most recent governors, I would characterize Kaine’s term to this point as belonging to the bottom quartile.

To be fair, he has a year and a half to go, and sometimes a Virginia governor can make a final push that raises his grade considerably.

So far, Kaine has had one shining moment after the Virginia Tech massacre in April 2007, when he handled the tragedy with aplomb — easily on a par with Gov. Frank Keating’s management of the Oklahoma City bombing in 1995 or Gov. Haley Barbour’s skill in bringing Mississippi back from the brink of chaos after Hurricane Katrina.

But otherwise, his executive tenure has recorded few significant successes and one giant, overriding failure in the transportation field where Kaine hoped to make his mark. Is Kaine solely responsible? Absolutely not.

4. The Aftermath in Virginia

Naturally, Obama would not be especially concerned about the post-Kaine era in Virginia, and given the frustrations of his governorship, one could hardly blame Kaine for grabbing a chance to move up and out — and eventually perhaps have his own shot at the presidency.

However, many Virginia Democrats were privately unhappy at the prospect of Kaine leaving in mid-term, potentially the first Virginia governor not to complete the single four-year term since it was established beginning in 1852.

That is because Kaine would have been succeeded by a deeply conservative Republican lieutenant governor, Bill Bolling. Being in office would have guaranteed Bolling the nomination if he should succeed to the top spot before the June 2009 nominating deadline. Thus, for the first time since 1852, an incumbent governor, Bill Bolling, would seek re-election.

Thus, Kaine’s departure could have delivered a five-year Bolling governorship, quite possibly followed by a term with another Republican. (The modern Virginia tradition has been to give a party at least two consecutive terms in the governor’s chair, even though the one-term-and-out rule means that different people would be elected every four years.) The Bolling term would include the redistricting year of 2011, possibly enabling Republicans to tenure in their state legislative and U.S. House incumbents for another decade. This would have wiped out Democratic momentum in Virginia.