Tarkanian had been positioning himself for a run to Heller's right, blasting the incumbent as a weak ally to Trump. But in what appeared to be an orchestrated move, Trump endorsed a Tarkanian House bid on Twitter on Friday, then Tarkanian quickly switched to the House bid.

The first public inkling of the plan came from Trump's tweet on Friday afternoon, hours before the filing deadline in Nevada.

"It would be great for the Republican Party of Nevada, and its unity if good guy Danny Tarkanian would run for Congress and Dean Heller, who is doing a really good job, could run for Senate unopposed!" he tweeted.

It would be great for the Republican Party of Nevada, and it’s unity if good guy Danny Tarkanian would run for Congress and Dean Heller, who is doing a really good job, could run for Senate unopposed! — Donald J. Trump (@realDonaldTrump) March 16, 2018

In a statement, Tarkanian said that both Trump and his political team reached out on Wednesday to ask him to reconsider his Senate bid and instead run in the 3rd district. Tarkanian lost to Rosen by just 1 point in 2016.

Tarkanian said that, while he hadn't planned to drop out of the Senate race before he heard from Trump, he wanted to abide by the president's request.

"I am confident I would have won the US Senate race and done a great job representing the people of Nevada in the Senate, but the President is adamant that a unified Republican ticket in Nevada is the best direction for the America First movement," Tarkanian said.

"With President Trump's full support and endorsement, I am filing to run again in CD3 with the firm belief that we will finish what we started in 2016 and win in 2018."

Rosen's bid for Senate leaves behind a competitive House seat in a district Trump narrowly won in 2016. Tarkanian will join a crowded field of candidates looking to make it through a large primary and face off in the key district.

The challenger had initially been seen as a minor stumbling block to Heller, but Tarkanian gained steam amid Heller's public waffling over health care. Tarkanian landed the support of former White House chief strategist Stephen Bannon, who had once been seen as the leader of an insurgent conservative movement launching primary challenges after Republican senators.

But while Tarkanian briefly rose in the polls, that momentum was undercut by Bannon's public falling out with the White House. All the while, Trump had appeared to be warming up to Heller— reportedly telling RNC members last month that he would campaign on Heller's behalf.

Tarkanian has also been dogged by financial issues that the Heller campaign had seized on to frame him as an opportunist.