President Donald Trump remains outraged by the repeated opposition he has faced from libertarian-leaning Rep. Thomas Massie (R-KY), who has spoken out or voted against Trump's actions and policy agenda on multiple occasions.

On Monday, Trump reiterated his vow to replace Massie in Congress via the primary election process in Kentucky and called for a challenger to emerge that he could endorse, Fox News reported.

In doing so, the president labeled the congressman as "the worst" among his fellow Republicans on Capitol Hill, and declared him to be a "real loser" and a "guaranteed NO VOTE" on the things that are important to the MAGA base.

Trump wants a primary challenger against Massie

Monday evening, in a Truth Social post, President Trump wrote, "Thomas Massie, the worst Republican Congressman, and an almost guaranteed NO VOTE each and every time, is an Embarrassment to Kentucky."

"He’s lazy, slow moving, and totally disingenuous -- A real loser! Never has anything positive to add," the president continued. "Looking for someone good to run against this guy, someone I can Endorse and vigorously campaign for!"

Trump's post included a link to a video ad produced by a group known as MAGA KY that urged Kentuckians to "Fire Thomas Massie."

The video noted that Massie has previously voted alongside "radical Democrats" in opposition to Trump's tax cuts, funds to finish construction of the border wall, and a ban on taxpayer-funded sex change operations for minors.

Also included in the video was a clip of Trump saying that Massie is a "grandstander" who "should be voted out of office."

Trump vowed to campaign in Kentucky against Massie

It was just one month ago, after Rep. Massie strongly objected to President Trump's ordered airstrikes on Iran's nuclear facilities, that Trump let loose with a lengthy message that said, "Congressman Thomas Massie of Kentucky is not MAGA, even though he likes to say he is," and further stated, "He is a negative force who almost always Votes 'NO,' no matter how good something may be."

Trump went on to accurately predict that Massie would "undoubtedly vote against the Great, Big, Beautiful Bill, even though non-passage means a 68% Tax Increase for everybody, and many things far worse than that."

"MAGA should drop this pathetic LOSER, Tom Massie, like the plague!" he added. "The good news is that we will have a wonderful American Patriot running against him in the Republican Primary, and I’ll be out in Kentucky campaigning really hard."

Massie "isn't worried" about Trump-backed primary challenge

In response to President Trump's continued threat to back a primary challenger against Rep. Massie, NBC News reporter Sahil Kapur shared that the Kentucky congressman said he "isn't worried" and believes he will ultimately "prevail" and be re-elected.

Massie also stated confidently that Trump's effort to oust him from Congress would "backfire tremendously," in that the president's allies were "wasting millions of dollars against me, and they're gonna lose the majority because of that."

He added that the effort could likewise "embolden" other Republicans who've previously been "quietly agreeing" with him to begin speaking out more forcefully in opposition to the president about issues on which they disagree.