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Louisiana State Treasurer John Fleming announced a bid to unseat Sen. Bill Cassidy, a Republican who voted to convict following the House impeachment vote against former President Trump in the wake of the Jan. 6, 2021, Capitol riot.

Fleming, a former U.S. congressman, was one of the founders of the conservative House Freedom Caucus, according to a press release about his Senate bid.

"Senator Cassidy has failed the people of Louisiana," Fleming said, according to the press release. 

"I will fight to bring real, conservative solutions to the U.S. Senate, I will not cut-and-run on these conservative principles, and I will stand and work with President Trump like I have many times before," he declared.

A Cassidy spokesman said in a statement to Fox News Digital, "This week, Senator Cassidy met with President Trump's VA nominee, secured tax relief for the victims of natural disasters in Louisiana and elsewhere, passed bills to reduce maternal mortality and to make it easier to donate to Veterans organizations, pushed Chuck Schumer to hold a vote to repeal WEP and GPO, and continues to work on important legislation. The time will come to focus on the campaign, and when that happens, he will see who is still in the race."

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John Fleming

Rep. John Fleming, R-La., candidate for the U.S. Senate from Louisiana, conducts a campaign rally at Drusilla Seafood Restaurant in Baton Rouge, Louisiana, on Nov. 7, 2016. (Tom Williams/CQ Roll Call)

Fleming held posts in Trump's prior administration.

"I cannot fully express the deep sense of pride I have, having served President Trump in the West Wing of the White House as he was literally fighting for his political life against those who were attacking him and turning their backs on him," Fleming noted, "but the opportunity to stand with him for the principles of America First is why I seek to serve the citizens of Louisiana in the United States Senate."

Trump endorsed Cassidy for re-election in 2020, before the lawmaker became one of the Senate Republicans who voted to convict after the House impeachment vote against Trump in early 2021.

That Senate vote took place after Trump had already departed from office, and the number of senators who voted to convict failed to reach the threshold necessary for a conviction.

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Sen. Bill Cassidy

Sen. Bill Cassidy, R-La., attends a press conference at the U.S. Capitol in Washington, D.C., on Aug. 5, 2022. (Kevin Dietsch/Getty Images)

Trump lambasted Cassidy in posts on Truth Social earlier this year.

"One of the worst Senators in the United States Senate is, without question, Bill Cassidy, A TOTAL FLAKE, Republican though he may be," Trump declared on April 1.

"Bill Cassidy is now shunned in his own State as a disloyal lightweight, and it’s a beautiful thing to watch," Trump declared in another post.

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Sen. Bill Cassidy

Sen. Bill Cassidy, R-La., listens to testimony from U.S. Trade Representative Katherine Tia during a Senate Finance Committee hearing on Capitol Hill in Washington, D.C., on March 31, 2022. (Drew Angerer/Getty Images)

Cassidy's current Senate term ends in early 2027.

Fleming previously ran unsuccessfully for Senate in 2016.