When Sen. Rick Santorum (R-Pa.) and his Democratic challenger Bob Casey Jr. met last week, viewers saw a lot of mud slung.
Last night in Philadelphia, though, the candidates for U.S. Senate focused more on another strategy - substance.
While the pair certainly traded their share of barbs, yesterday's debate at the National Constitution Center showcased little of the finger-wagging and name-calling that flooded last Thursday's debate in Pittsburgh.
Instead, Santorum defined his views on policy in Iran and North Korea, while Casey blasted the incumbent for his "rubber-stamping" of presidential policy.
Santorum said he would strike Iran if it developed nuclear weapons and would refuse to engage in bilateral talks with North Korea.
"You don't negotiate with terrorists," Santorum said. "Stalling for time is not in our interests. What we need to do is aggressively go after them and defeat them."
Casey, on the other hand, said the U.S. should exhaust all diplomatic options before once again resorting to military action.
He also criticized Santorum for his continued support of the Bush administration and the war in Iraq.
"Rick Santorum once again reiterated what his campaign has been about. It's been about more of the same," Casey said. "He's satisfied with where we are in Iraq. He's satisfied that this country is doing everything possible to protect our people from terrorism, and I don't agree."
As the debate turned to domestic issues, the candidates focused on illegal immigration, which has been a point of conflict throughout the election.
Santorum accused Casey of supporting amnesty for illegal aliens and presented his record of voting for border security as evidence of his strong position on immigration.
Casey responded that Santorum has been hypocritical on the issue.
The final statements for the two politicians illustrated the major themes of the year-long campaign - Casey as the candidate for change and Santorum as a dedicated public servant.
"The bottom line is that I've worked hard for the people of Pennsylvania. I had to earn this job," Santorum said.
After the debate, both sides claimed victory, but Temple University Director of the Institute of Public Affairs Michael Hagen said that neither candidate made enough of an impression to move public opinion.
"I don't think there are a whole lot of people left who are likely to vote on election day in Pennsylvania who haven't made up their mind," he said.
Hagen added that while Santorum certainly has a chance, something drastic will have to happen in the coming weeks for him to catch Casey, who has led by double digits in some polls.
Last night's debate, moderated by ABC News' George Stephanopoulos, was the last of four Pennsylvania Senate debates this year.
