Sen. Tim Kaine says voters who want to cast a vote for the Johnson/Weld ticket should look to history. "The third party candidacy of Ralph Nader cost Gore electoral votes in New Hampshire in Florida," Kaine tells Yahoo Global News Anchor Katie Couric. "And if Gore had been president, we probably wouldn't have had a war in Iraq. Casting a protest vote for a third party candidate that's going to lose may well affect the outcome, and may well lead to a consequence that is deeply, deeply troubling."