With President Donald Trump’s “revenge tour” against Republicans complete, he has successfully ousted several congressional Republicans — with one more possibility on the way — but by doing so he has severely imperiled his critical majority in the U.S. Senate.“One understated reality of what Trump has done: He basically just nuked his Senate majority for the next six months,” writes political journalist Isaac Saul. Saul explains that U.S. Senator Bill Cassidy (R-LA), who recently lost his primary to a Trump-endorsed MAGA rival, “now has no reason to play ball.” Cassidy this week scorched two key items on President Trump’s agenda: his $1.8 billion victimization and weaponization fund, and the $1 billion for security enhancements for his ballroom.“People are concerned about paying their mortgage or rent, affording groceries and paying for gas, not about putting together a $1.8 billion fund for the President and his allies to pay whomever they wish with no legal precedent or accountability,” Cassidy wrote on Wednesday in a rare rebuke from a sitting GOP lawmaker. “This is adding to our national debt. If there needs to be a settlement, the administration should bring it to Congress to decide.” Earlier this week, Cassidy said, “I just know where I am on the ballroom.”He blasted the administration for what he said was not getting bids, or doing the architectural, engineering, environmental, or historic work.“And so they don’t know how much money they should ask for, but they picked a number,” he said. “That’s not the way to run the government,” Cassidy added. “So they just want a pot of money, and I think they need to give us more detail.”Then there’s U.S. Senator John Cornyn (R-TX), who lost an endorsement battle to his MAGA rival — whom Trump endorsed on Tuesday, one week before the primary runoff.Saul notes that Cornyn “will have to navigate the runoff, but win or lose next Tuesday he comes out of that doing whatever he wants.”He also points to U.S. Senator Thom Tillis (R-NC) who “is retiring and already acting like an independent.” And U.S. Senators Lisa Murkowski (R-AK) and Susan Collins (R-ME), who “have long been willing to break with POTUS.”“All the sudden,” Saul explains, “a 53-47 Senate majority is a 48-47 majority with five live swing votes.”As Punchbowl News reported on Thursday, Senate Republicans are “preparing to buck President Donald Trump on two of his long-running obsessions: the White House ballroom project and the ‘weaponization’ of federal agencies against his allies.”Those are the two issues Cassidy has been railing against.