There are other and newer considerations. Garner signed on because F.D.R. needed the Texas delegation's votes at the 1932 convention. Now you don't. The choice may say something about the presidential candidate. Geography hardly matters anymore.
Religion does, a bit.
Bush should pick Christie Todd Whitman of New Jersey. I doubt very much that either Kerrey or Whitman will be in the race this year. I simply say they would be the running mates who would bring the most to each ticket. But in politics, antipathies may be temporary. Once in 1990 I sat in Senator Al Gore's office in Washington and asked him what he thought of Bill Clinton of Arkansas.