Republican candidate Mitt Romney announced Saturday that his running mate for the White House is congressman Paul Ryan (R-Wisc.). Already, the pundits are asking whether Ryan will put Wisconsin in play or if Ryan will bring in support from Catholics. If past research predicts the future, he will give Romney a short-term bump in the polls and then barely affect the final election results.
Research on the effects of running mates on presidential elections consistently finds marginal effects for vice presidential picks. At best, there is less than 1 percentage point change in the nationwide vote or in the VP candidate's home state, while some studies have found that running mates have no effect on the vote at all.
Even in 2008, when former Alaska governor Sarah Palin rocketed into national politics, Republican candidate John McCain's pick brought in few additional votes. In fact, comedian Tina Fey's impersonation of Palin may have been more effective in changing votes than the real-life candidate.
But running mates can change a campaign even if they do not change the election outcome. Ryan may be most effective not as someone who garners votes but as one who starts debates. As chair of the House Budget Committee, Ryan presented and passed in March the “Ryan Plan,” a bold and controversial budget. It included changes to domestic programs including funding cuts, privatization, and block-grants. The changes were so ambitious that former Speaker of the House Newt Gingrich criticized the Ryan Plan as “right wing social engineering.”
Ryan, a practicing Catholic, took heat from some religious leaders who called his plan immoral. Sojourners and other non-Catholic religious groups criticized ...