House Republicans' campaign arm is reaching out to Republicans who may have faced problems at their polling locations during Tuesday's Pittsburgh-area special election as they gather information for a potential recount.

Republicans are eager to hold off a defeat in the district, which voted forby 20 points in the 2016 presidential race. Lamb's lead and the district's apparent swing toward Democrats has been seen as a sign that Democrats could take back the House majority in November.

But Republicans are preparing for a potential recount or lawsuit challenging those results. The new ad campaign is a way for the National Republican Congressional Committee (NRCC) to collect information about any potential issues ahead of those challenges.

as of the latest tally after the Tuesday election in the 18th District

as of the latest tally after the Tuesday election in the 18th District

Democrat Conor Lamb has 627 more votes than Republican state Rep. Rick Saccone as of the latest tally after the Tuesday election in the 18th District , with just a few hundred provisional and military votes left to be counted.

The GOP's outreach to voters in the district is coming in the form of Facebook ads, detailed exclusively to The Hill, targeting 200,000 Republican voters in the district with a call to reach out to the NRCC if they faced problems while they cast ballots.

"URGENT: Are you a Republican that tried voting in the March 13 special election but faced issues at your polling location? If so, we need to hear from you! The election depends on it," the ad reads.

Voters can click to send a message to the NRCC's legal defense program about their issues and will receive a response from one of the NRCC's lawyers.

The NRCC says they've received more than 50 responses already.

The fact-finding mission comes as Republicans gear up for a possible challenge to Tuesday's results.

Pennsylvania has no automatic recount trigger for congressional races, but groups of voters can petition for a recount once the votes are counted. Republicans have also said they could file a potential lawsuit stemming from their concerns about the results.

A source familiar with the process told The Hill on Wednesday that Republicans are demanding that the district impound ballots and voting machines for a potential recount.

A lawyer with the Saccone campaign sent a letter of objection to the Allegheny County Election Division on Wednesday that claimed that the district frustrated a Saccone campaign official's attempt to witness vote counts in that county.

There are also claims of other potential irregularities that The Hill could not independently confirm — including a charge that touch-screen voting machines in Allegheny County were miscalibrated, and another that the Pennsylvania secretary of state's new website prompted confusion among voters.

The 18th District special election was held under old congressional lines, but the state Supreme Court adopted new lines last month that will go into effect by the May primaries.