Donald Trump’s MAGA allies are racing to put down the last vestiges of Republican resistance to him in the Senate. Following her initial hesitance toward Pete Hegseth, Trump’s embattled Defense Secretary pick, Sen. Joni Ernst came in for a raft of criticism from Republicans in her home state of Iowa. Sen. Bill Cassidy, one of four remaining senators who voted to impeach Trump in 2021, just drew a formal primary challenge. And moderate Sens. Susan Collins (R-Maine) and Lisa...