Newswise — While Sarah Palin has energized the campaign of John McCain, political scientist Andrew Dowdle of the University of Arkansas suggests that the effect of her celebrity has peaked.

"Historically, the vice presidential candidate hasn't played a role at all in how an election plays out. No matter how much attention the VP gets during the campaign, people vote for the president.

"Sarah Palin has certainly made the race a lot closer. The gap between the two candidates usually closes somewhat when the partisans come back to the fold, as the election gets closer. My guess is that she's brought the GOP stragglers home a bit earlier than usual, but I suspect her surge in popularity has peaked. If I were advising the Democrats, I'd tell them to ride it out and start going after McCain on the issues, especially the economy."

Dowdle is an assistant professor of political science in the J. William Fulbright College of Arts and Sciences at the University of Arkansas and editor of The American Review of Politics.