Mark Halperin gives his "Head and Heart" picks for Obama and McCain:

McCain's head pick: Mitt Romney

Obama's head pick: Evan Bayh

McCain's heart picks: Lindsey Graham, Tom Ridge

Obama's heart picks: Tim Kaine, Kathleen Sebelius

McCain's head/heart picks: Joe Lieberman, Bobby Jindal

Obama's head/heart picks: Chris Dodd, Joe Biden

On McCain's end, an interesting omission from Halperin is Tim Pawlenty, who probably is a runner-up "head pick."