Rep. Paul Ryan of Wisconsin campaigns in Glen Allen and Springfield Friday, less than a week after Mitt Romney unveiled him as his running mate in Norfolk.

Republican vice presidential candidate Representative Paul Ryan (R-Wis.) speaks during a campaign rally at Miami University in Oxford, Ohio, Aug. 15, 2012. (Aaron P. Bernstein/Reuters)

Romney, President Obama and their high-profile surrogates have made multiple visits to the key swing state, where Obama leads Romney 51 percent to 44 percent among registered voters, according to a new Washington Post poll.

After Romney and Ryan made appearances Saturday, Vice President Joe Biden campaigned this week in Virginia.