When a Senator chooses to identify with the Republican party, than during the election year announces he will not vote for their presidential candidate (when he could just keep his mouth shut if he prefers not to give endorsement) I give him no credit at all. It is one thing to be a Liberal Republican. It is another to use the Party to be elected, than disregard the Party to be for all intent a Democrat.
At that point the cord need to be cut.