Cruz is not likeable.
I did not realize GOP voters were this stupid.
Trump came and campaigned for Cruz. Cruz has been one of the best Trump allies in the US Senate.
It is a binary poltical system. Either the R controls or the D controls the Congress.
If R control Trump gets to set the Legislative agenda, if Ds control Trump can do nothing.
If you support Trump, you go out and vote for every single R candidate no matter what. To not vote for Cruz is an act of infantile petulance, not principal.