Tarkanian had been positioning himself to run to the right of Heller, making the incumbent a weak ally of Trump. But in what appeared to be an orchestrated movement, Trump endorsed an offer from the Tarkanian Chamber on Twitter on Friday, then Tarkanian quickly switched to the House offer.
The first public indication of the plan came from Trump's tweet on Friday in the afternoon, hours before the presentation deadline in Nevada.
"It would be great for the Nevada Republican Party, and its unity if good guy Danny Tarkanian ran for Congress and Dean Heller, who is doing a really good job, could run for the Senate without opposition!" he tweeted.
It would be great for the Nevada Republican Party, and it's the unity if the good guy Danny Tarkanian comes to Congress and Dean Heller, who is doing a very good job, could run for the Senate without opposition.
– Donald J. Trump (@realDonaldTrump) March 16, 2018
In a statement, Tarkanian said that both Trump and his political team approached on Wednesday to ask him to reconsider its candidacy to the Senate and in its place it is executed in the 3rd district. Tarkanian to Rosen for only 1 point in 2016.
While Tarkanian said that while he had not planned to leave the Senate race before learning about Trump, he wanted to comply with the president's request. 
"I'm sure I would have won the race in the US Senate and I've done a great job representing the people of Nevada in the Senate, but the President insists that a unified Republican ticket in Nevada is the better direction for the America First movement, "Tarkanian said.
"With the support and full support of President Trump, I am submitting an application to present again on CD3 with the firm conviction that we will finish what we started in 2016 and win in 2018"
Rosen's offer for the Senate leaves behind a competitive seat of the House in a district that Trump narrowly won in 2016. Tarkanian will join a crowded field of candidates seeking to overcome a large primary and face in the key district.
The challenger had initially been seen as a small obstacle for Heller, but Tarkanian gained strength amidst Heller's public mockery about medical care. Tarkanian gained the support of former White House chief strategist Stephen Bannon, who was once seen as the leader of an insurgent conservative movement that launched primary challenges after the Republican senators.
Now with her way clear, Heller will likely face Rosen in the general election, since she is the main candidate on the Democratic side.