“It's crazy. I do worry about the Republican party," McCain said, as quoted by the Daily Beast. "It’s the first time I’ve ever seen Republican senators running ads, raising money to attack other incumbent senators. I’ve never seen that in my life. It’s terribly wrong.”
According to a New York Times report, Sen. Ted Cruz (R-TX) was berated by his colleagues during a recent closed-door meeting for not renouncing attacks on fellow Republicans levied by an unnamed "conservative group." Politico reported that those attacks came from the Senate Conservatives Fund, a group which has aligned itself closely with Cruz.