FAYETTEVILLE, N.C. — President Donald Trump put his political prowess on the line on Monday, campaigning here on the eve of a special election seen as a bellwether for his own contest next year.

The president's gamble: that the last-minute stop — where he painted a dark picture of threats from immigration, crime and socialism — could help tip the scales in favor of House Republican candidate Dan Bishop.

“Tomorrow is your chance to send a clear message to the America-hating left,” Trump told the crowd in Fayetteville.

On paper, despite the electoral controversy that's rocked the district over the past year, the race between Bishop and Democrat Dan McCready should be a shoo-in for Bishop — who is, after all, running in a district Trump won by 12 points in 2016.

Instead, it’s a dead heat, fueling jitters among Republicans still reeling from heavy losses in the House of Representatives in 2018.

A win by McCready would send a dramatic warning sign to Republicans over their 2020 chances; even a narrow GOP victory in the deep-red district would be cause for concern.

Sparking even more anxiety for the party is the fact that North Carolina, which Trump won by less than 4 points in 2016, is seen as a key swing state for 2020.

Back in Washington, Trump faced renewed investigations by Democrats as they returned Monday from their summer recess. Members showed no signs that the break in their district had convinced them to let up on their probes.

The House Judiciary Committee laid out specific committee procedures that could set the stage for a vote this week to define the committee’s impeachment investigation.

Trump only made passing mentions to the prospect of impeachment.

“They tried the recession thing, they tried the Russia thing, didn’t work," Trump said, accusing those warning of a weakening economy or pushing for investigation of Russian efforts to aid his campaign of looking to those issues to prevent him from getting re-elected.

House Democrats also said they are investigating both Vice President Mike Pence’s stay at Trump’s Ireland resort and an overnight stop by Air Force crew members at the president's Scotland property. The House Judiciary Committee is separately investigating whether the president has run afoul of the Constitution's Emoluments Clause.

He made no mention of those or two other controversies that have encompassed his presidency in recent days — a breakdown in talks with the Taliban, and his continued insistence that Hurricane Dorian was set to hit Alabama days after meteorologists had ruled out that possibility.

While Trump trailed off-topic at times — musing about how he looks better under the light of incandescent bulbs, and surveying the crowd on whether they prefer to hear an item is “Made in America” or “Made in the USA” — he mostly stuck to his scripted talking points and avoided shifting attention away from the purpose of his rally: keeping Republicans in the House from losing yet another seat to the Democratic majority.