Casey, 52, son of the late Gov. Robert Casey Sr., and a former state treasurer and auditor, bested a jittery Smith in their lone debate and withstood an onslaught of attack ads with a somewhat low-key campaign; Ed Rendell called it a "non-campaign" last month.
Smith, 65, a high-school-educated former coal miner who made millions running his own company, dumped $17 million of his personal fortune into the race and blasted Casey on TV as "Senator Zero."
But a seat in the Senate - some call it "the world's most exclusive club" - apparently costs a tad more.
Casey, who unseated U.S. Sen. Rick Santorum in 2006, had the advantage of a popular name and a winning combination of policy positions: Pro-life, pro-gun, pro-labor. Smith, by contrast, ran as a staunch fiscal conservative who called global warming a hoax and said that he'd consider eliminating the Department of Education.
Pennsylvania Democratic Party Chairman Jim Burn said that Smith's money couldn't make up for a lack of a message that appealed to voters.
"You can have all the money in the world," Burn said. "How many Pennsylvanians can find common ground with a man who can throw $15 million dollars into a race because he has nothing else to do?"
Casey, whose victory likely puts him in the pool of potential Democratic gubernatorial candidates in 2014 or 2018, is the first Pennsylvania Democrat in a half-century to win a second Senate term.
Staff writer Chris Brennan contributed to this report.
Contact William Bender at firstname.lastname@example.org or 215-854-5255. Follow him on Twitter @wbender99.