When Democrat Katie McGinty faces Republican Sen. Pat Toomey on Monday in the first debate of their hotly contested U.S. Senate race, analysts in both parties will be watching to see if the challenger can live up to the moment.
McGinty has fought to a tie or small lead in most public polls. But in their first formal confrontation, Republicans believe the Democrat, who has never held elected office, will pale next to a sitting senator - and Democrats acknowledge she has to show the political heft to oust an incumbent.
"Toomey is on defense right now, but this debate is an opportunity for him to try to turn the tables, because he is probably a more seasoned, more skilled debater, having run for office before," said Mark Nevins, a Democratic strategist based in Philadelphia. "McGinty is not as seasoned."
The one-hour debate will tape Monday afternoon at Pittsburgh's KDKA-TV and air at 7 p.m. that night. A second and final debate is scheduled for Oct. 24 in Philadelphia.
Toomey, a former businessman who has been in the political arena for nearly 20 years, including three U.S. House campaigns and two bruising Senate races. He has experience sharpening his arguments for public jousting and has pressed for more debates.
McGinty, by contrast, has spent her career largely behind the scenes as Pennsylvania's environmental secretary and Gov. Wolf's chief of staff.
In only her second campaign, she finds herself in a contest with national significance. She has appeared more comfortable in public appearances as her campaign has gone on, but has faced criticism for leaning on party talking points.
"There's some question marks about just how good a candidate she is," said Christopher Borick, a Muhlenberg College pollster. "I think she can go a long way to alleviating those concerns with a really good debate performance against a very well-equipped opponent."
Borick has served as moderator for Toomey's debates in past elections. He said the Republican doesn't get flustered.
"He stays on message, he's got a pretty level persona," Borick said. "He might not win you over with excitement, but he certainly doesn't do himself any damage."
While much of the Senate race has been overshadowed by this year's vitriolic presidential contest, the Senate debates will put the candidates on center stage.
Charlie Gerow, a Republican consultant from Harrisburg, predicted that McGinty would falter "under that kind of scrutiny."
Toomey has faced relentless pressure from McGinty and reporters for his refusal to say if he will support Republican presidential nominee Donald Trump.
But in a likely preview of an argument to play out Monday, he countered last week by arguing that he is "an independent voice" while saying McGinty's endorsement of Hillary Clinton shows she is a partisan "rubber stamp."
"I have demonstrated time and again that I am willing to work with people in either party, work across the aisle, and find solutions that are right for Pennsylvania," he said Thursday in a call with reporters. "My opponent in this race cannot make the same claim at all."
He amplified the message in a new TV ad, saying he "will stand up to any president's bad ideas."
As evidence, Toomey points to his work with Democrats on a bill to expand background checks for gun purchases - which won support from President Obama, former New York Mayor Michael Bloomberg, and former Democratic Congresswoman Gabrielle Giffords - and bills he cosponsored with Democrats.
He and top Republicans from the Pennsylvania legislature, meanwhile, attacked McGinty on Thursday as a "hyper-partisan," blaming her for Pennsylvania's long budget stalemate when she was Wolf's top aide.
Democrats dismissed Toomey's claims, pointing to his 94 percent lifetime rating from the Club for Growth and 96 percent score from Americans for Prosperity, two staunchly conservative groups that disdain compromise.
And McGinty mocked Toomey's ad for claiming he has "backbone" - when he won't say whom he supports for president.
"Senator Pat Toomey now has the distinction of being the only Senate candidate in the United States of America to refuse to come clean about whether or not he supports Donald Trump," she said on a call with reporters Thursday, challenging him to finally take a stand in the wake of claims that Trump sexually assaulted several women.
She then launched a TV ad linking Toomey and Trump, saying they are "too dangerous for Pennsylvania women."
Toomey has not endorsed Trump - but he has also not ruled out eventually supporting his party's nominee.
In a meeting with Inquirer editors and reporters, McGinty argued that she helped make bipartisan progress on key issues in Harrisburg, including a new school-funding formula.
Asked about the differences between her and Clinton, McGinty said she would oppose closing the military prison on Guantanamo Bay, unlike the Democratic nominee. She also cited the 2013 bipartisan immigration reform bill as the kind of legislation she would work on with Republicans.
On policy, the two Senate nominees fall into predictable camps.
Toomey is a fiscal hawk who wants to see fewer regulations on businesses and lower taxes across the board, along with a simplified tax code. In his Inquirer visit last week, he blasted the Federal Reserve's monetary policies, called for a more formal budget process, and supported the elimination of the Consumer Financial Protection Bureau, created to protect consumers from banking abuses. He argued that it is too powerful and that other agencies can pursue banks' wrongdoing.
McGinty argues Toomey would "take the cop off the beat," pointing to the bureau's role in levying a $100 million fine against Wells Fargo for the bank's misconduct.
A longtime environmentalist, she says her ideas would help working families: providing paid family leave, boosting Social Security benefits, raising the minimum wage to $15, and making college more affordable. She says she would avoid tax hikes on middle-class families but would support increases on the wealthy.
Toomey says her program would mean more taxes and spending.
He opposes the Iran nuclear deal. McGinty supports it. He would repeal the Affordable Care Act. McGinty sees it as a positive that needs tweaking.
When the issues are litigated on the debate stage, Nevins said, McGinty may simply have to hold her own. Senate debates don't draw huge audiences, and the only way they usually make a major impact is if one candidate makes a gaffe that becomes news.
Sticking to the script, he said, may work just fine.