Republican Rep. Thomas Massie of Kentucky has faced a barrage of attacks from President Trump heading into Tuesday's primary against former Navy SEAL Ed Gallrein, who has the president's endorsement. 

But Massie doesn't appear to be sweating it, even after several of Mr. Trump's perceived adversaries have suffered primary defeats stemming from the president's ire — most recently GOP Sen. Bill Cassidy of Louisiana. 

In the days leading up to the contest in Kentucky's 4th Congressional District, Mr. Trump has labeled Massie "the worst congressman in the history of our country" and has called him "a disloyal, ungracious, and sanctimonious FOOL." He has also threatened to primary other congressional Republicans who have campaigned with Massie, who has voted against several of the president's legislative priorities, opposed the war with Iran and defied him in pushing for the release of the Epstein files. 

"He knows I'm tough to beat," Massie told CBS News in an interview Monday in his hometown of Vanceburg, Kentucky. "He's literally losing sleep over this race, because he's in with both feet. I think their polling shows what our polling shows, which is there's a better than half chance that we're going to win this race." 

Massie later said, "I'm going to win." 

Defense Secretary Pete Hegseth campaigned with Gallrein earlier Monday in a hotel ballroom across the street from the Cincinnati/Northern Kentucky Airport, using a 23-minute appearance to accuse Massie of "constant obstruction." Hegseth said he was there in his personal capacity, and after stopping earlier Monday at the Fort Campbell Army Base, though the visit marked a break from military officials' longstanding practice of avoiding partisan politics. 

Massie told CBS News that Hegseth's appearance underscores how concerned the president and his allies are about Tuesday's outcome. 

"How much personal time do you have when you're supposed to be monitoring a war in Iran?" Massie said. "You don't send the Secretary of War to Kentucky during a war if you think your candidate is up 10 points. That's what you do when you realize your whole campaign is imploding." 

But Massie said millions in spending by pro-Israel interest groups is causing more disruption in the race than the president. In a typical year, Massie said he would have won the primary with 80% of the vote. He estimated Mr. Trump's endorsement of Gallrein lowered his support to 60%, and spending from the pro-Israel lobby further eroded it. 

"I think what would have been a 60-40 race is now a 50-50 race," Massie said, citing Gallrein's support from AIPAC, the Republican Jewish Coalition and GOP megadonors such as Miriam Adelson. 

The congressman called the race, which has become the most expensive House primary in history, "a referendum on whether the Israeli lobby can buy a seat in Congress." He accused the interest groups of trying to "intimidate the entire Republican Party into having zero dissension on foreign policy toward Israel." 

Massie is one of the few Republicans in Congress who has opposed the war with Iran and has voted with Democrats to rein in Mr. Trump's authority to carry out further military action without congressional authorization. He has also voted against symbolic resolutions backing Israel, as well as a resolution condemning antisemitism that he argued promoted censorship.

Asked whether he's antisemitic, Massie responded "hell no." 

Massie warned that it's a "big disfavor" to Jewish Americans to equate anti-Zionism or criticism of Israeli Prime Minister Benjamin Netanyahu's war in Gaza with antisemitism. 

He defended his stance on Israel, saying his policy has "always been no country is special and no country deserves my constituents' taxpayer dollars." 

"I have never voted for foreign aid to Egypt, to Syria, to Israel or to Ukraine," he said. "But the ones in Israel, since they're the biggest recipients of it, that makes them a little bit mad." 

Massie said he doesn't support aid to Israel because "we've got debt" and it's a "one-way" arrangement. 

"At least with NATO, there's the promise of a reciprocal arrangement," he argued, also accusing Israel of dragging the U.S. into wars.