Representative Thomas Massie (R-KY) isn’t losing any sleep over Donald Trump’s latest outburst. In fact, he says he’s immune. During an interview Monday on MSNBC’s All In with Chris Hayes, Massie reacted to a scathing Truth Social post from the president by saying he’s developed “Trump antibodies.”

Hayes opened the segment by highlighting Massie’s long history of being a lone voice in Congress. “You’re the single, solitary no vote on that Big, Beautiful Bill,” Hayes noted, referencing Trump’s latest legislative push.

But the real heat came from Trump’s response to that vote, where he branded Massie a “simple minded grandstander,” claimed the MAGA base doesn’t like him, and accused him of siding with Iran’s nuclear ambitions while disrespecting the military. The post, typical of Trump’s unfiltered style, ended with him calling Massie a “pathetic loser.”

Rather than fire back with equal venom, Massie played it cool. “Well, you know, I tweeted his message to me and I said, the president’s declared war against me so much I think he needs an act of Congress to validate this,” Massie joked.

When Hayes chuckled and said he saw the tweet, Massie added dryly, “In some sense I have the Trump antibodies.”

The exchange underlines a longstanding tension between Trump and Massie, who has often stood apart from the former president on major legislation. Massie’s vote against what Trump has dubbed his “Big, Beautiful Bill”—a sweeping package that Trump claims will revive U.S. energy, manufacturing, and infrastructure—sparked the latest round of attacks.

Despite the insults, Massie seems to be betting on political resilience over confrontation. His jab about needing “an act of Congress” to validate Trump’s repeated hostilities is vintage Massie: principled, sarcastic, and largely unfazed by populist pressure.

While Trump still wields significant influence over the Republican base, Massie’s independence has earned him a niche following among liberty-minded conservatives who prioritize limited government over party-line obedience. Whether this latest dustup costs him politically remains to be seen—but judging by his calm demeanor and quick wit, he doesn’t seem particularly worried.

As 2025’s legislative battles unfold, Massie is positioning himself as both a thorn in Trump’s side and a symbol of intra-party dissent. His “antibodies” line may become a defining quote for Republicans who resist the Trump tide without aligning with the establishment.