While Cruz is a thumper, he is also Hispanic, and  huge thorn in the foot of the establishment. He won't be seen as a Washington insider, not after his battles with McConnell.  

I think Cruz makes a much better running mate than someone like Rubio, Rubio comes across as yet another slick politician. Cruz is anything but "slick"  

As I have already conceded Cruz is too much of a thumper for me to vote for him at the top of the ticket, but the fact that much of Washington hates the guy is a huge positive IMO, and I think it will sell well with the American public who is fed up with Washington.