According to a new poll, President Obama leads Republican challengers in Pennsylvania, and his approval ratings are on the rise.

The Public Policy Polling survey has the president with a 47% approval rating in Pennsylvania, up from 42% in 2011.

PPP Director Tom Jensen said Obama leads Republican frontunner Mitt Romney by seven points in the Keystone State, 49-42. The president also leads home-state candidate Rick Santorum by two points in the poll, 48-46.

Jensen said more independents have turned to Obama over the last year, and the prolonged Republican primary battle is turning people sour on all the GOP candidates.

"This is something we've seen not just in Pennsylvania, but across the country as the Republican nomination contest has sort of dragged on, is that the candidates are getting less and less popular," said Jensen. "Only 30% of voters in the state have a favorable opinion of Mitt Romney, 60% unfavorable; and home-state candidate Rick Santorum [is] not much more popular."

However, Jensen said the president had been having problems with the state of Pennsylvania until recently, "because it's one that Democrats really expect to win on a cycle-by-cycle basis, and his numbers there, up until this poll, had been pretty atrocious. This recovery, I think, is very good news for Obama's reelection prospects nationally, because I think if he wins Pennsylvania, he'll get reelected overall."

In the Republican primary race, native Santorum is ahead of Romney by 18 points in Pennsylvania, his widest lead in the country.

The poll shows that Santorum has strong support from religious voters and the ‘very conservative’ subgroup of the Commonwealth.