Via RCP, the key words are “as we know it.” The obvious rebuttal is that the Democratic Party “as we know it” didn’t go extinct in 1988 when it lost its third election in a row. It nominated a southern candidate in 1992 who tacked towards the center and ended up holding the White House for the rest of the decade. But Democrats then weren’t in the position that the GOP’s in now. There was no significant third-party movement-in-waiting on the left like there is on the right with the tea party. How many presidential losses will it take to cause a rupture?
Let’s say we nominate another establishment favorite; Jeb is the likeliest bet, but if he doesn’t run, it could be that the donor class lines up behind Christie and buys him the nomination. Imagine he loses to Hillary. Losing three presidential elections in a row with three candidates disdained by the GOP base guarantees some sort of shake-up for 2020. Either conservatives really will start leaving the party in droves or, in order to keep them in the tent, establishmentarians will have to throw them a bone and embrace a more grassroots candidate for the next election. The status quo, where the party perennially puts forth centrists while its core constituency clamors for someone more ideological, couldn’t continue. At a minimum, tea partiers would conclude that if they’re going to have their hearts broken every four years, they might as well do it with their own nominee, whom they respect, than climb aboard the GOP’s train to nowhere.
Now let’s say that tea partiers somehow manage to thwart the establishment this time. Imagine that Jeb falls flat for dynastic reasons, Christie flames out because of Bridgegate, and Rubio can’t get traction as a last-ditch back-up establishment choice. Ted Cruz stuns the world in Iowa and New Hampshire and wins the nomination — and then he loses to Hillary. Where does the party go from there? The base’s longstanding thesis, that the GOP would surely recapture the White House if it put forth a loud-and-proud “true conservative” as nominee, would be shattered. But centrists, having lost with McCain and Romney, wouldn’t be in a position to capitalize. I don’t know what happens to at that point (although grassroots righties would probably blame the RINOs for stabbing Cruz in the back and demand a do-over with another right-wing candidate next time), but the pressure on both sides to find a winning alternative in 2020 would be immense. Neither party has won four elections in a row in the age of presidential term limits. The idea that the GOP would change fundamentally somehow in order to prevent it isn’t entirely out of left field.
The X factor here is if it nominates Rand Paul in 2016 and he ends up losing. I can see both sides treating that as an aberration — establishmentarians would cite it as a lesson of what happens when you nominate someone beloved by the base and tea partiers would claim that Paul wasn’t a true conservative but rather a quirky libertarian whose eccentricities ultimately tripped him up. That would, in theory, reset the whole game for 2020, with centrists insisting that only a pro-amnesty hawk will play in the purple states and grassroots righties insisting that they still haven’t had a chance to see how one of their own, like Cruz or Palin, would fare as nominee. In that one (and only one) weird sense, Rand Paul is the guy most likely to preserve the Republican “status quo” until the end of the decade.