Running Mate 'Bounce' Doesn't Climb Very High

Much ink has been spilled over Barack Obama and John McCain’s upcoming VP selections, but a running mate is not a game-changing choice, the Chicago Tribune reports. History suggests the effect on opinion polls will be noticeable but not huge: Gallup shows recent candidates getting an average 5% bump after announcing their picks.

Bob Dole got the biggest lift when he selected Jack Kemp, but even that only served to take him from 30% to 39%. Most recently, John Kerry saw a mere 4% boost after selecting John Edwards, and that bump evaporated within 10 days. Even that mini-surge looked big compared to George W. Bush’s 3% Cheney bump. The picks also did little to dent opposition support, which generally holds steady through the announcements. (More vice presidential sweepstakes stories.)