(CNN) When President Donald Trump heads to western Pennsylvania on Saturday, he'll be trying to save a struggling Republican congressional candidate locked in a tough special election race.

He'll also be trying to save himself and his party from an embarrassing defeat in a district he won by 20 points in 2016 and one filled with the white, blue-collar voters who led him to victory.

The White House scrambled to vet the order Trump signed Thursday after he made it known that he wanted to approve the tariffs before his campaign stop on Saturday, where he is set to hold a rally for Republican state Rep. Rick Saccone.

The President's moves on tariffs this week were, in part, designed to gin up support for Saccone; Trump has told associates that he hopes the tariffs will play well with his base, including voters in Pennsylvania 18th District around Pittsburgh and in the heart of America's steel industry.

But the tariffs, some Republicans said, may not be the silver bullet Trump is hoping for.

A source familiar with the inner-workings of Saccone's campaign has said that tariffs are not an issue that moves the needle for them, largely because his Democratic opponent Conor Lamb is also supportive of the tariffs.

The moves on trade could also be a misreading of the district as a whole. A GOP operative noted that a portion of the district in Allegheny County is also suburban, with a diverse economy.

"The Steel Curtain is gone," the operative said in a reference to the Pittsburgh Steelers' famed 1970s defense. "People aren't showing up to work with hard hats and lunch pails anymore."

Trump and the Republican Party have already been pulling out all the stops to bolster Saccone in Pennsylvania.

Trump, who tweeted his "total support" for Saccone in January, also gave him a shoutout at a rally in Pennsylvania earlier this year. And Republican groups have spent around $10 million on the race to keep Saccone competitive with Democrat Conor Lamb, who outraised Saccone nearly five-to-one in the first seven weeks of the year.

If Saccone loses on Tuesday, it would mean that Trump and the party couldn't save a Republican candidate running in the heart of Trump country, and it would signal more danger for Republicans in the midterm elections come November.

While district offers a window into blue-collar voters' thinking of Trump's job performance, the result itself will have no impact on party control of the House in the midterms. Pennsylvania's Supreme Court has redrawn the districts, with Lamb and Saccone both living outside its new boundaries. The winner Tuesday will only represent the current 18th District until January.

As the race comes to a close, Republicans are already pinning the blame of a potential loss on Saccone and his poor fundraising abilities.

Republican sources confirmed that Rep. Steve Stivers, the chairman of the National Republican Congressional Committee, warned the 60-year-old Saccone early this year that his fundraising needed to improve dramatically and has nudged Saccone along in several additional conversations. The exchange was first reported by Politico.

The committee sent a staffer to teach Saccone how to raise money. One GOP source said Saccone had no fundraising network and didn't even appear to have a legitimate recordkeeping system in place early in the campaign.

"It's not a lack of effort, it's a lack of ability," the operative said of Saccone's struggles.