Will Ted Cruz get primaried in his re-election bid in 2018? If yes, by who?

[Atlas Has Shrugged]

The only way I can see this happening is if some other Tea Party person of equal stature challenges Cruz along with an establishment type. Let's say Robert Paul, son of Ron Paul and brother of Rand, actually runs (he has resisted draft attempts and clearly has absolutely no interest at all in politics, but whatever, this is just a bland hypothetical) and gets ~12% of the vote while Mike McCaul runs with establishment support. This scenario still doesn't guarantee McCaul winning a majority and avoiding a runoff that Cruz would easily win.