At WORST, some Cruz staffers and supporters ran with a story on CNN that wasn't vetted. That's far from what I'd consider "cheating" like Clinton's buddy Donald Chump said (after all the insults, lies, flip flops, and birther crap from him)
Donald Chump the RINO lost by over 6000 votes. Ben Carson would have had to lose about 30% of his own votes - all to Cruz for this to have been won based on "dirty tricks" (let alone cheating or fraud).
Rove's threatened by Cruz's disdain for him and the Washington Cartel, so he's going to help anyone over Cruz.