But poll director G. Terry Madonna cautions that the numbers will shift as we move closer to the April 24 primary election here.
"I'm not saying he won't win the state," Madonna said of Santorum, who has enjoyed a burst of Republican support after other primary candidates challenged Romney's perceived front-runner status, but then flamed out. "I'm saying he won't hold on to that kind of lead."
And Santorum could erode his lead if he continues to veer off-message about the nation's economy - consistently the most pressing concern among voters in the poll - and presses forward on social issues like contraception and women in the military.
"We know he can come unplugged," Madonna said. "He showed remarkable discipline when he was letting all these other candidates implode."
Forty-five percent of the Republicans polled said that they had not made up their minds about which candidate will get their vote.
There are 186 days until the Republican National Convention begins in Tampa, Fla.
Madonna noted that a plurality of Santorum supporters picked Romney as their second choice. The same was true of Romney backers with Santorum.
Fifty-six percent of those polled said that Pennsylvania was heading in the wrong direction, while 31 percent said that the state was heading in the right direction.
President Obama's numbers in Pennsylvania are as steady in the polling as they are unimpressive. In a statistical tie, 49 percent of the registered voters in the poll don't want him to have a second term, while 47 percent support it.
But paired against the four Republican candidates in general-election matchups, Obama beats Santorum, 45-37 percent; Romney, 41-33 percent; Gingrich, 47-31 percent; and Paul, 41-28 percent.
The 20th Republican debate of the campaign season was held last night in Arizona.
Twelve percent of the Republicans polled said that debates were the most important factor in their decision in supporting a candidate. Forty-five percent said that the debates were one of many factors, 29 percent called them a minor factor and 13 percent said that debates play no role.
Asked to rank what qualities matter most in a candidate, 36 percent of the Republicans said a strong moral character, 23 percent said the right experience, 18 percent said the ability to beat Obama, 13 percent said being a true conservative, 8 percent listed another quality and 2 percent said they did not know.