Priebus could try to strongarm the state party into prohibiting them from being on the ballot in those states in 2020/24 (depending on whether Trump wins this year), or strongarm the rules committee into not seating any delegates awarded to said candidates from those states, or only seating half of such delegates - on the basis that such candidates gave a willful oath to the party that should have consequences if it is ever broken.
I would say there is zero chance of any of that happening. It would look stupidly anti-democratic to try something like that--to basically disqualify candidates by fiat. The information is out there....about the pledges that they broke. Opposing candidates are free to use it against them. If the voters don't care and vote for them anyway, then why should the party chairman overrule them?
Priebus's argument seems to be that the pledge should have meant something, so there has to be a consequence for breaking it. If someone rescinded the pledge before a given primary, there would likely have been a move to take them off the ballot in that state. But the primaries have happened, so the punishment has to be something else. I guess Cruz can just be removed from congressional committees, but Jebra and Kasich aren't in Congress.
I think any "punishment" should be left to the voters to decide. Actually withholding delegates in a future presidential run by Cruz or Kasich, delegates that they would normally be awarded based on how many votes they get....it would look terrible. And it's not going to happen, because no one's going to care about Trump or this pledge anymore in three years.*
* That is, assuming Trump loses this November. If he wins, then he replaces Priebus at the RNC with his own cronies, and the "punishment" will be something more substantial than what's being contemplated here.
