"My opponent, Tom Smith, thinks we should take away the guaranteed benefit of Medicare and change it, either by giving someone a voucher, or changing it more radically," Casey said.
Smith, the Republican nominee, protested that he would not touch either Medicare or Social Security for older workers. But he said program changes might be needed to keep both programs going long-term. He said congressional Republicans have shown courage in even tackling the hot-button issue, while Casey and other Democrats have not.
He attacked Casey by excoriating his vote for the Affordable Health Care Act. He called the healthcare bill "one of the biggest power grabs in this country's history."
He asked TV viewers, "Do you really want to turn over one-sixth of the economy in this country to bureaucrats like the ones in the IRS and the post office.. . . Sen. Casey "is standing in the way of getting that appealed."
The debate was civil and an hour long. A little-known third candidate, Libertarian Rayburn Smith, of Clarion County, did not participate.
Casey, a veteran of numerous TV debates in four previous campaigns for statewide office, appeared relaxed and confident on the issues.
Smith, a coal-mining millionaire with no previous political experience except as a township supervisor in rural Western Pennsylvania, sometimes looked ill at ease, and twice referred to moderator Jim Gardner as "Larry."
He appeared more confident when articulating his general philosophy, including a closing statement in which he said that government spending - popular or not - must be curbed for the nation to prosper.
He noted that he had nine grandchildren, one of them just a month old.
"When that little fellow came into the world, he was $51,000 in debt because of our national debt," he said. ".. . . Who is going to stand up for our children and their children?"
The candidates differed over whether to extend into next year a 2 percent payroll tax cut that Casey said has benefited 6.5 million Pennsylvanians.
Casey pledged to vote to continue it.
Smith said "the people that helps, needed that help, I agree." But he declined to say he'd extent the cut. His aids said afterward he is opposed to doing so.
In proposing to eliminate the Department of Energy, Smith said its purpose when started in the Carter Administration in the 1970s, was to free the nation from dependence on foreign oil.
"Here we are, billions and billions of dollars later, and we're no closer than when we started," he said.
Smith said "it's possible" he'd favor getting rid of the Department of Education, too - though he'd still have federal money go to states for schooling.
Casey did not address the energy department, but he took issue with Smith on even talking about ending the education department.
"To eliminate the Department of Education doesn't make a lot of sense to me," he said. "I don't think there's much support for that."
The pair also disagreed on how they hoped the Supreme Court would rule on a legal challenge to affirmative action at the University of Texas, where as at most universities some admissions preference can be given to minorities.
Said Casey: "If the Supreme Court would make that decision [to end preferences], it would be a departure from where we have been for over a generation."
He said the country still has "a long way to go" in addressing racial inequality in education.
Said Smith: "I believe we should try to end discrimination and bigotry wherever we find it."
He suggested that preferences for minorities amount to discrimination against others.
"I don't think we should he discriminating against anybody," he said.
Contact Tom Infield at 610-313-8205 or firstname.lastname@example.org, or follow on Twitter @tinfield.