“Honestly, if you look at the polling in a general election setting, I don’t think it’s outside the realm of possibility that the seat [flips], depending on who the Democrats nominate,” said Senate Majority Leader John Thune, when asked about the possibility that Republicans could lose the race if Cornyn, who he endorsed, is not the party’s nominee.
If Cornyn loses the primary, Senate Republicans worry they could be forced to spend hundreds of millions of dollars that could otherwise go toward key battleground races in expensive states like North Carolina, Georgia or Michigan, complicating their path toward holding Senate control.