The next special election for a House seat has been set, with Gov. Tom Wolf (D-Penn.) scheduling the race to replace former representative Tim Murphy (R-Pa.) for March 13.

Like 2016’s four special House elections, which were held to replace Republicans who joined the Trump administration, the race in Pennsylvania’s 18th District will take place on Trump-friendly turf. The president won 58.1 percent of the vote in the district, a stretch of rural areas around Pittsburgh that had been drawn by Republicans in 2011 to favor Murphy, who resigned after advising a woman with whom he had an extramarital affair to get an abortion.

Still, the opportunity to compete in an open seat has attracted something Murphy didn’t have to face in 2016: Democratic candidates. Before Murphy announced his resignation, three Democrats were already running for the 2018 nomination. Two more have jumped in since then, with Democrats especially intrigued by Conor Lamb, an assistant U.S. attorney and Marine veteran.

“It tilts Republican but can be competitive with the right candidate,” said Mike Mikus, a Pennsylvania Democratic strategist who helped former congressman Mark Critz win a 2010 special election to replace the late John P. Murtha in the neighboring 12th district.

In Pennsylvania, candidates for special elections are nominated by party leaders, not in primaries. Lamb is seeking the same nomination as Gina Cerilli, a commissioner in conservative Westmoreland County; Mike Crossey, a former teachers union president; Navy veteran Pam Iovino; and physician Bob Solomon. Four Republicans have piled into the race for their nomination, all of them state legislators, one of whom — Rep. Rick Saccone — bailed on a long-shot challenge to Sen. Robert P. Casey Jr. (D-Penn.) to run.

National Democrats have said little about the race in the 18th District, which on paper has few of the features that characterize swing seats. Its electorate is more than 90 percent white and wealthier than the neighboring 12th District — the one once held by Critz — thanks to some of its suburbs and the area around Pittsburgh’s airport.

But the southwest Pennsylvania district looks like many that Democrats held before 2010, with a voter registration advantage for the party of nearly 70,000 but an electorate that typically votes Republican for president. In 2010 and 2012 — when he narrowly lost reelection but ran ahead of Barack Obama — Critz ran a jobs-focused campaign, attacking free trade deals and blurring the lines on social issues and guns.

The parties will pick nominees later this year.