Professor Larry Sabato of the University of Virginia Centre for Politics, whom I admire for his broad, historically attuned knowledge of US politics, has a thorough essay examining the potential choice of Virginia governor Tim Kaine for Obama's vice-presidential candidate. Kaine has been getting a lot of attention in recent days, as Obama campaign sources have let it be known the campaign is looking hard at him.
Sabato writes that the "personal chemistry" the two share is the biggest factor in the plus column:
There can be little doubt that this is the main reason why Obama is looking at Kaine. The first state governor outside Obama's Illinois to endorse Obama for President, Kaine was immediately drawn to the Illinois senator because they are two peas in a political pod. Both Harvard Law graduates with Kansas roots, both attorneys with a central focus on civil rights, and both relatively new to the big leagues, Obama and Kaine clearly like one another and enjoy each other's company.