There are several swing states presidential candidates hope to lock up to secure their win in general elections, and Pennsylvania is one of them.

But Campaigns & Elections magazine has broken down the swing votes by county. If likely Republican candidate Mitt Romney hopes to unseat President Barack Obama, he's going to need help from Chester County. According to the publication, Chester is No. 7 on a list of 10 U.S. swing counties. Hillsborough County, Fla., is No. 1 and Forsynth County, N.C., is No. 10.

George W. Bush won Chester County in 2004, and Obama won the county in 2008.