How would I know WHO would primary him, in a few years? Did anyone know who all was going to run in the GOP presidential primary THREE YEARS AGO? I didn't; did YOU?
Because you can’t beat a somebody with a nobody. I’ve seen these bullcrap posturings from people claiming Cruz is some left-winger RINO and Conservatives are all lining up to challenge him in 2018. Fact is, you can’t produce a name. Not one.
If you knew anything about politics, you’d know names well ahead of time. I knew about Zero when he ran for Congress against Bobby Rush in 2000, long before he appeared on the radar screen. I knew about Sarah Palin when she was still Mayor of Wasilla in 2001 ginning up for a run for Lieutenant Governor of Alaska.
Did I know in 2013 who was going to run for President in 2016 ? Well, yes, yes, I did. I knew Cruz would be the standard bearer for Conservatives coming into the Senate. Trump, while a surprise, has really been planning to run for President since the 1980s, but waiting for the right moment to have a go, and this election proved his moment to pull the trigger.
As an aside, you have to be prepared to run for President at least 3-4 years ahead of time these days because of the sheer amount of money and assembling of a campaign required. That may increase over the coming decades, 8-12-16 years, because you will need to assemble a multi-billion dollar warchest.