The 60-minute debate was moderated by Action News anchors Matt O'Donnell and Sharrie Williams, along with Univision 65's Ilia Garcia.
The candidates touched on a wide range of topics, such as clean energy policy, gun laws, and abortion rights. They disagreed on nearly all of them.
Following the charged debate, Action News reporter Caroline Goggin spoke with David Barrett, a political science professor at Villanova University.
Barrett said he found the debate to be 'very predictable.'
"Both candidates did what the campaign consultants advised, which is attack, attack, attack. Repeat the same slogans over and over," Barrett explained. "So, there wasn't much that was original in this debate. It's hard to see how the debate would have a great effect on the election outcome."
While the candidates debated a variety of key topics, Barrett said one of the most important issues they spoke about was abortion.
Both Casey and McCormick explained discrepancies in their positions.
WATCH | Full 6abc debate between Bob Casey, Dave McCormick
Watch the full 6abc debate between Bob Casey, Dave McCormick
Casey -- a one-time self-described "pro-life Democrat" -- voted in favor of the right to an abortion under the Roe v. Wade standard after the U.S. Supreme Court reversed its 1973 landmark decision on abortion rights.
Casey said most Americans believe daughters shouldn't have fewer rights than their mothers.
No senator "has flip-flopped more on this issue," McCormick rebutted.
McCormick, who supported the high court's 2022 decision to end federal protection of abortion rights, tried to moderate his opposition to abortion rights.
Now, he said, voters -- not courts -- get to decide whether a state will protect the right to an abortion, even if it means some women don't have that right, and he reiterated that he wouldn't vote for a federal abortion ban.
Barrett said it seemed like Casey had an advantage in that exchange.
"It seemed to me that Mr. McCormick was uncomfortable on that issue - trying to portray himself as a moderate, which makes sense politically in Pennsylvania, where I think this issue is mainstream," Barrett said.
Speaking on the debate as a whole, Barrett said, "I think these are indeed a public service. It gives the candidates a chance to make their case. I just wish candidates were more willing to forget what the campaign consultants say."
With three weeks until the election, and the polls showing this race is close, Barrett suggested the key for Casey will be to win over some independent-minded voters who might be having second thoughts about him.
"For McCormick, he does still have the problem of a topic that Senator Casey raised, which is he really a Pennsylvanian or not?" Barrett said. "He has been behind in virtually all of the polls and the real challenge for him is how do you get those extra couple of percentages of votes?"
Speaking about the importance of this race, Barrett told Action News, "There's a handful of Senate races that could go either way, and what happens in those states really determines what kind of Senate we're going to have - Republican or Democratic majority."
The Associated Press contributed to this report.