The Pennsylvania district is a mix of working-class rural areas and affluent suburbs populated with mostly white voters. The district was once considered favorable territory for conservative Democrats and Democrats still have a voter registration advantage, but now the district reliably votes Republican. Trump won the Pennsylvania district by 20 points and in 2012, Mitt Romney won it by nearly 17 points.

It’s not yet clear how much of a chance Democrats will have. The Cook Political Report initially rated the race “Likely Republican” after Murphy’s resignation, but has since changed its rating to “Lean Republican,” indicating that the election could be competitive.

Nationally, Democrats have a number of advantages heading into elections in 2018. The president’s party usually loses seats in the midterm elections, and Trump’s approval ratings remain at historic lows. Democrats have performed better than expected in special elections in 2017, and have turned out to vote in high numbers relative to Republican voters. That adds up to a favorable landscape for the party.

Even so, that may not be enough to overcome the advantage Republicans have in the conservative Pennsylvania district. It hasn’t been enough in any other House special election held under the Trump administration so far. In the past year, Democrats have lost a string of high-profile House seat special elections in red districts in Kansas, Montana, Georgia, and South Carolina.

Along with national factors, the Pennsylvania special election will be influenced by local forces like the quality of the candidates running and how well they match up to the district.

Lamb, a former federal prosecutor and military veteran, is so far running as a centrist Democrat. His campaign has chosen to emphasize a record of fighting the opioid epidemic, and taking on drug dealers and violent criminals.

Conspicuously absent from the Democratic candidate’s campaign website is any mention of hot-button issues like abortion and gun control laws (though it does say he has led prosecutions against gun traffickers). In interviews, Lamb has said that “choice is the law of the land.” He has said that he is “pro-Second Amendment,” though he thinks that “we need to have the conversation” about gun control.

“This district as a whole is a pro-life, pro-Second Amendment type of place and the Republican nominee is kind of standard issue conservative Republican on those issues,” said Christopher Nicholas, a Republican political consultant based in Pennsylvania. “The district is not going to elect someone who can’t tell you where they stand on abortion and isn’t a strong Second Amendment supporter.”

Saccone is also a military veteran and, despite the anti-political establishment backlash, he seems to think his track record as a legislator is an advantage. His website warns that “Congress Is No Place for On-the-Job Training.” It goes on to describe Saccone as a champion of lower taxes, cutting government waste, creating jobs, and protecting the United States from the threat of terror.