[Just to be clear, I am not claiming that any of the following is inevitable or even likely, but I do think it falls in the category of things to consider.]
We've been arguing for quite a while now that the conservative movement's social engineering experiment has achieved its considerable success over the past few decades at the cost of exposing the party to genuinely existential threats. I had meant to precede this post with a bit more foundation, but events seem to be accelerating and I need to get this down.
Political parties have survived major rifts before. We could find numerous notable examples for both Democrats and Republicans, and, in all of those cases, the wounds were real but temporary. However, these divisions, though bitter, took place in broad-based relatively healthy political parties, I would argue that the Republican Party of 2017, though nominally controlling most of the government, is perhaps uniquely fragile and cannot survive a nasty internal conflict.
Here is a scenario of how such a conflict can arise and grow into an existential threat. I won't say that it is probable, but I think each link in the chain is definitely plausible. This is certainly true for the first link since between the time I outlined the concatenation of events and the time I sat down to write this, the first one had already happened. (That's why this is something of a rush job.)
First, a bit of background from our game theory post back in February (Charles Schumer predicted a break between Trump and the party in three or four months. I said a year of two. Perhaps we should have split the difference):
The relationship between the Trump/Bannon White House and the GOP legislature is perhaps uniquely suited for a textbook game theory analysis. In pretty much all previous cases, relationships between presidents and Congress have been complicated by numerous factors other than naked self-interest--ideological, partisan, personal, cultural--but this time it's different. With a few isolated exceptions, there is no deeply held common ground between the White House and Capitol Hill. The current arrangement is strictly based on people getting things they care about in exchange for things they don't.
However, while the relationship is simple in those terms, it is dauntingly complex in terms of the pros and cons of staying versus going. If the Republicans stand with Trump, he will probably sign any piece of legislation that comes across his desk (with this White House, "probably" is always a necessary qualifier). This comes at the cost of losing their ability to distance themselves from and increasingly unpopular and scandal-ridden administration.
Some of that distance might be clawed back by public criticism of the president and by high-profile hearings, but those steps bring even greater risks. Trump has no interest in the GOP's legislative agenda, no loyalty to the party, and no particular affection for its leaders. Worse still, as Josh Marshall has frequently noted, Trump has the bully's instinctive tendency to go after the vulnerable. There is a limit to the damage he can inflict on the Democrats, but he is in a position to literally destroy the Republican Party.
We often hear this framed in terms of Trump supporters making trouble in the primaries, but that's pre-2016 thinking. This goes far deeper. In addition to a seemingly total lack of interpersonal, temperamental, and rhetorical constraints, Trump is highly popular with a large segment of the base. In the event of an intra-party war, some of this support would undoubtedly peel away, but a substantial portion would stay.
Keep in mind, all of this takes place in the context of a troubling demographic tide for the Republicans. Their strategic response to this has been to maximize turnout within the party while suppressing the vote on the other side. It has been a shrewd strategy but it leaves little margin for error. Trump has the ability to drive a wedge between a significant chunk of the base and the GOP for at least the next few cycles, possibly enough to threaten the viability of the party.
With that in mind, consider the following possible developments:
1. Trump fires Reince Priebus. Keep in mind, the choice of Priebus was (probably accurately) seen as an early indicator that, for all of his outsider talk, Trump intended to run a partisan administration with close ties to the Republican establishment. The firing has to be seen as a weakening of that relationship;
2. After ever increasing harassment, Jeff Sessions jumps or is pushed out of the administration;
3. This, along with other transgressions, prompts Graham and a few other Republican senators to start actively pushing for investigations into and greater accountability from the White House;
4. The strongest remaining link between the administration and the GOP establishment, vice president Mike Pence, is finding it increasingly difficult to keep his skirts clean from the Russia scandals. He does his best to distance himself and, as a result, further marginalizes his role;
5. Further developments in the Russia scandal exacerbate existing tensions;
6. While Trump does have his loyalists and the number of Republicans willing to publicly attack him remains fairly small, the majority of the party starts to see the president as a dangerous liability and attempts to distance itself from him, whenever possible refusing to take sides;
7. Angry at the lack of loyalty and feeling pressure from the investigations, Trump escalates his attacks on the GOP;
8. (Any of the following)
a. Trump fires Mueller
b. Mueller or some other investigator uncovers a major criminal conspiracy involving Trump, his family, or his business
c. Polls start showing serious erosion in support for Trump and the GOP in the conservative base
d. Things just keep getting ugly
9. At some major events such as a large rally or even the state of the union address, Donald Trump announces that, in the tradition of Teddy Roosevelt, he has realized that both parties are hopelessly corrupt and the only way to drain the swamp is by starting a third-party. So it is his intention to run in 2020 as the candidate for the MAGA Party and to field candidates in every major statewide contest.
Now, I want to be careful about how we frame this. Trump forming a third party remains unlikely, but it would not that unlikely if we hit events 1 through 8 and, taken individually, none of these events seem all that improbable.
I should probably polish this post a bit more, but given the pace of things these days, you have to make your predictions as quickly as possible.