“We woulda won if it wasn’t for @%#! Trump.”
That won’t be true, but it will at least give them a convenient excuse and allow them to continue to evade the real truth: namely, that the predilections of old white Southern men are not shared by a majority of Americans.
“Hillary Clinton was very successful because I went to bat for her. All the candidates were coming to me asking for my help, but Hillary, she was offering more money than you could believe. She wouldn’t have won if I hadn’t been in her corner, but people all around the country respect my opinion. I’m a very intelligent man, and when I say this is the right woman for the job, people listen.”
-Donald Trump
“Whatever we did, we’ll do even better next time if we just do more of it!” (Or “if we’re even more conservative”.)
That too! Gotta love it. 
Jeb lost because he wasn’t conservative enough. Next time we’ll nominate a true believer, I swear! We’ll have a secret meeting on Jan 20, 2017 and pledge to not support an single thing that Hillary wants to do.
“We woulda won if those @%#! hadn’t torpedoed Trump’s candidacy.”
Ha, that one might well be an alternate possibility.
“Tea Party, you had your chance with Trump. You did not lead, we will.” or “We must move this party to the center on hot button issues now that our record from 1992-2016 is worse than the Dems from 1968-1988.”
That one is not happening except for a tiny number of think tankers and center right pundits.
“If only Mitt would have run a third time.”
“We will do whatever is necessary to ensure that Hillary Clinton will be a one-term President.”
This is a very good possibility.
“Well, it’s still a conservative nation.”
Most likely indeed. Although if Trump was the nominee that will be said by the Republicans about any Democrat that is the new president.
Why only if he was the nominee?
(To clarify, my implicit supposition in the OP is that he will run as another Perot in the general.)
“We will do whatever is necessary to ensure that Obama will NOT have a fourth term as President.”
Gawd damn, we couldn’t even buy a win.
^ Good one!
One thing they’ll be saying is the same thing they’ve been saying after every election they’ve lost that I can remember: “They paid the niggers, spics, and bums to vote”. Please excuse my language but it is an actual quote.
In seriousness, it will publicly be “we lost to the biggest political machine in America.” In private, the moderates will come back with force.
In reality, I think it will be the death of the Tea Party. I think the Tea Party exists in part because some feel Republicans don’t listen to their more conservative views. If Trump or Cruz gets the nod and loses, the Tea Party guys will have a tough time claiming to be unlistened to. I think Trump or Cruz will run hard against illegal immigration, which is almost the common thread among all TP factions.