PENNSYLVANIA is still considered one of nine swing states in the 2012 race for the White House, but a Daily News/Franklin & Marshall College Poll released Wednesday shows President Obama holding a comfortable lead of 12 percentage points over former Mass. Gov. Mitt Romney.

Registered voters favor Obama 48 to 36 percent over Romney, with 12 percent undecided and the rest answering "don't know."

Obama led Romney by 8 percent in a February poll, when the Republican presidential primaries were still in contention.

The new poll found opinions hardening, with 82 percent saying they were certain about which candidate they would support.

Voters polled had more confidence in Obama on economic issues, social issues such as abortion and gay marriage, foreign policy and understanding the concerns of Americans.

Still, one in three voters had a strongly unfavorable opinion of Obama, and one in four voters was undecided about Romney.

Gov. Corbett does not seem well-suited to serve as a local surrogate for Romney, who locked up enough delegates in last week's Texas primary to clinch the Republican nomination. Twenty-five percent of those polled have a strongly unfavorable opinion of Corbett, up from 17 percent in January, tracking a trend that started in the fall of 2010.

The other high-profile race in the Nov. 6 general election, U.S. Sen. Bob Casey's bid for a second term, doesn't look likely to add much heat to the presidential election. Casey leads Republican nominee Tom Smith, a former Armstrong County coal-company owner who financed his campaign with $5 million of his own money, 42 to 21 percent, with 35 percent undecided.

Crossroads GPS, a Republican super-PAC organized by former Bush White House staffer Karl Rove, started airing a new TV commercial Tuesday evening in Pennsylvania, accusing Obama of "reckless spending" paid for by loans from China.

Brad Woodhouse, spokesman for the Democratic National Committee, called that claim an "absolute joke" and "revisionist history" that ignores the economic impact of wars in Iraq and Afghanistan along with tax cuts for the wealthy, all coming during former President George W. Bush's two terms in the White House.

Franklin & Marshall College Poll Director G. Terry Madonna wonders if third-party spending like Crossroads GPS is having much of an impact on the race.

"Obama's job performance has been steady for two or three months," Madonna said. "Everyone is running a lot of commercials, but it's not making a huge difference."

For Madonna, the real question is whether Pennsylvania becomes competitive in the presidential election. He predicts that won't be known until September.

Romney can take solace in the fact that his campaign hasn't been that active in Pennsylvania because the state's April 24 primary election had little impact on the GOP nomination, Madonna noted. But Pennsylvania voters also are likely to zone out on the race over the summer months, he added, as Romney seeks their support against Obama.