Because the way things are going now, if they steal the nomination or create a third party to throw the election (which Trump and the RNC agreed not to do) the Republican Party will lose just about everything. Maybe some state governors and legislatures will be left in place, but not if they're part of the scheming.
JMHO
I have been busily processing that possible future for a few weeks now. It always seems to lead to a civil war revolving around the second amendment. This is why I am all about the NRA remaining non-partisan.
I have to wonder why if the GOPe has screwed over voters for years now as we all know, they are so opposed to Trump. Cruz supporter think Trump is another elite. If that were the case they would welcome him. Instead they will do literally anything to stop Trump. This whole election is stop Trump at any cost.
Cruz supporters seem to miss that the people that hate Trump the most and fear his stopping their activities are the same people who have lied and cheated and used voters for year.
Go Trump!
If all of the Republicans are against us, who is there left to be for us? I mean, how can we find enough clean candidates to contend?