HARRISBURG - Tom Wolf had been heavily favored in polls for almost two months to win the four-way Democratic gubernatorial primary election before an opponent pulled the trigger on a TV attack ad against him.
Five more TV attack ads followed in the last three weeks, including one by the Republican incumbent, Gov. Tom Corbett, as Wolf's foes made a calculated bet that the risky strategy was the only way to beat him.
They bet too late, it seems.
Wolf is polling so far ahead that a victory by any other Democrat in the May 20 primary election would amount to the most dramatic comeback in Pennsylvania's modern political history.
"It would be, in my humble judgment, without precedent," said G. Terry Madonna, a pollster and a professor of public affairs at Franklin and Marshall College in Lancaster.
Christopher Borick, a political science professor and pollster at Muhlenberg College in Allentown, echoed that sentiment.
"It's certainly a formidable challenge to reel him in at this point," Borick said. "It's just looking at the math."
So far, three polls in the race have shown Wolf leading by at least 20 percentage points, with the most recent one surveying voters in late April. Overcoming such a large polling deficit is certainly possible, but Madonna and Borick could not recall it ever happening in Pennsylvania in such a short stretch of time.
They acknowledge it is more difficult to produce an accurate poll when voter turnout is low. Without a hot-button issue to motivate the electorate, perhaps 1 million registered Democrats, or one in four in Pennsylvania, will vote in the primary.
"The smaller the turnout, the more difficult it is to predict the exact nature of who will vote," Madonna said.
The latest independent poll, by Muhlenberg College, surveyed 417 likely voters in the last three days of April. It showed Wolf winning easily with 38 percent, even as 33 percent remained unsure about which candidate they will support. The other 29 percent were divided among state Treasurer Rob McCord, former Clinton White House environmental adviser Katie McGinty and U.S. Rep. Allyson Schwartz.
That poll's results were very similar to two earlier Franklin and Marshall College polls. New polls are forthcoming from both schools this week and could show what kind of damage, if any, the attack ads inflicted on Wolf's popularity.
Wolf's advantage started with his spending advantage - the wealthy businessman is helping his campaign outspend McCord's and Schwartz's by $5 million. That gave him the ability to start airing daily TV ads Jan. 30, seven weeks before his first competitor did.
The TV ads were widely praised as effective, featuring his take on key issues, his family and his employees while bringing a relatively unknown candidate to life in a folksy, apolitical way that seemed to resonate with registered Democrats, such as university administrator Bruce Taggart.
"Wolf has the best ad/media campaign I've seen in many years," said Taggart, a suburban Allentown resident who was undecided before he saw Wolf's ads.
The advertising delivered a huge lead to Wolf in a field of Democratic competitors, who, despite far more experience in politics and government, had relatively low statewide name recognition.
Even so, McCord and Schwartz can claim advantages that Wolf lacks: McCord has captured the endorsements of the state's major labor unions, while Schwartz has a congressional district of voters who have elected her five times and the Philadelphia city Democratic Party behind her.
But for all the millions of dollars McCord and Schwartz have spent - bolstered with daily attacks on Wolf by Corbett and the state Republican Party - it is not clear it had much effect. No candidate has released an internal poll that casts doubt on the results of the public polls.
That might reflect the persuasiveness of Wolf's ads. It also might reflect a backlash against candidates who go negative.
For Corbett, who has no primary opponent, the risk is lower. But for McCord and Schwartz, who are attacking a fellow Democrat, the risk is greater, Borick said.
Teacher Bonne Bosco of Allentown said she had been split between supporting Wolf and McCord - until McCord's attacks on Wolf prompted her to lean toward Wolf.
"I just feel that no Democrat should be running negative ads against someone in their own party. It's a big turnoff for me," she said. Still, "I could change my mind in a week. My opinion isn't set in stone."
Levy covers politics and government for The Associated Press in Pennsylvania. He can be reached at firstname.lastname@example.org.