Vice-presidential candidates customarily do not drive vote choices, but there may be an exception: If John McCain were to pick a running mate who favors legal abortion, it could cost him votes, particularly in some core Republican groups.
In this ABC News/Washington Post poll, 20 percent of McCain supporters say they'd be less likely to vote for him if he picked a pro-choice candidate for vice president.
(ABC News Photo Illustration)Among current McCain supporters, 20 percent in this ABC News/Washington Post poll say they'd be less likely to vote for him if he picked a candidate for vice president who favors legal abortion, vs. 10 percent more likely – a 10-point net negative, and one he does not make up among Barack Obama's supporters.
The potential damage is sharper in some groups. Twenty-seven percent of conservatives say they'd be less likely to support McCain if he picked a vice president who favors legal abortion, vs. just 3 percent more likely – a net 24-point negative in this heavily Republican group. It's similar among evangelical white Protestants; 29 percent say such a pick would make them less likely to vote for McCain, vs. 6 percent more likely, a 23-point net negative.
http://abcnews.go.com/PollingUnit/Conventions/story?id=5669316&page=1