Sen. Luther Strange, R-Ala., Tuesday called for a change to the Senate filibuster rule and sided with President Trump over Senate Majority Leader Mitch McConnell, R-Ky., as the campaign heats up to retain his seat.

Strange made the call in a letter to McConnell and Senate Minority Leader Chuck Schumer, D-N.Y. The move would lower the filibuster threshold from 60 votes to 51 votes, a simple majority.

"Alabamians overwhelmingly supported the election of Donald Trump to the White House and expect his agenda to be enacted by Congress. But, because of obstructionist tactics by Democrats and broken promises by some Republicans, very little legislation is even making it to the Senate floor," Strange wrote in the letter.

"While I had hoped that Republicans and Democrats would work together to accomplish the will of the American people, it has become obvious that politics and self-preservation will continue to rule the day," Strange said.

"Conversations with the president have led me to the conclusion that changing the filibuster rule is the only way we will be able to build the border wall, rein in sanctuary cities, defund Planned Parenthood, and give the American people real tax relief.

"It's time to give our president and the American people what they are asking for," he added.

Trump has been a loud advocate for the change, which McConnell has resisted and shot down in recent months. He made his most recent push for the change nearly two weeks ago

"If Republican Senate doesn't get rid of the Filibuster Rule & go to a simple majority, which the Dems would do, they are just wasting time!" Trump tweeted on Aug. 23.

Strange is in a fight for his political life with Roy Moore, the former chief justice of the Alabama Supreme Court.

According to the latest RealClearPolitics average, Moore leads the incumbent Republican by 10.2 points (45.5-35.3 percent) in the race to fill Attorney General Jeff Sessions' seat through 2020.

Strange is losing despite earning Trump's endorsement during a primary contest battle with Rep. Mo Brooks, R-Ala., to earn a runoff against Moore.

However, since then, Trump has stayed silent and has declined to comment on the race. Along with Trump, McConnell has been a top backer of Strange's campaign as the Senate Leadership Fund, a super PAC run by allies of McConnell, continues to back the incumbent.

In a statement, Moore campaign chairman Bill Armstead said that the move shows that Strange "will say anything" to hold onto his seat and called the announcement a "blatant flipflop."

"Luther will say anything to keep his seat in the club for Washington elites," said Armstead. "Yesterday Luther supported the filibuster. Today he opposes it. This is a blatant flipflop that career politicians do when they're in trouble. Judge Moore has been very clear on this issue, supporting President Trump, while as late as April of this year, Luther Strange was signing letters to McConnell with John McCain and Jeff Flake pledging his support for the filibuster. How can Alabamians trust Luther Strange if he will say anything to get elected and put the senate club's rules over the interests of America?"