I'm afraid that the reputation Cruz earned... of not being particularly well liked by his colleagues... which some initially took on as a badge of honor... is coming back to haunt him.
There are times when you need political allies, and this is one of those times for Cruz.
I suspect this would be playing out differently if it were Jeff Sessions on the hotseat. He's every bit as conservative as Cruz, but I've heard that he is admired by most of the Senate, even the dimocrats don't actively dislike him personally.
Jeff Sessions is very fine example with no baggage and an impeccable reputation. He is my pick to share the ticket with TRUMP, if Donald just must have a pol on the ticket. Sessions is the sage of the senate and has been a tireless researcher on all these urgent issues that are especially vital to our country and to conservatives, and he “do” know the Senate, inside out.