Rank-and-file Republicans have signaled their disaffection from their party in spectacular fashion, from the Tea Party to the summer of Trump. The reason of the Republican revolt is not hard to explain: disappointment and frustration.

Donald Trump was propelled into first place among Republicans in July 2015 much more by anger against the party’s existing leadership than by any attraction he exerted on his own. Listen for a minute to conservative radio host Mark Levin on the six-day Trump-Fox feud after the first presidential candidates’ debate:

Senator Mitch McConnell and Representatives John Boehner and Karl Rove and their ilk …. You’re sick of them. You’re sick of them not doing what you elected them to do. You’re sick of them lying to you. You’re sick of them attacking everybody who doesn’t agree with them through their surrogates. You’re sick of how they treat people who dare to challenge them in Republican primaries … You’re tired of so-called conservative commentators on TV and elsewhere who serve as their surrogates ... You don’t feel you have a home and you don’t feel that there’s a party that stands up for you.

Levin expressed with extra vehemence a view that is surprisingly widespread among rank-and-file Republicans.

And it didn’t start in 2015, either. The influential conservative-leaning election analyst Sean Trende observed after House Majority Leader Eric Cantor lost a primary election in 2014 that:

[A]nalysts need to understand that the Republican base is furious with the Republican establishment, especially over the Bush years. From the point of view of conservatives I’ve spoken with, the early- to mid-2000s look like this: Voters gave Republicans control of Congress and the presidency for the longest stretch since the 1920s.

And what do Republicans have to show for it? Temporary tax cuts, No Child Left Behind, the Medicare prescription drug benefit, a new Cabinet department, increased federal spending, TARP, and repeated attempts at immigration reform. Basically, despite a historic opportunity to shrink government, almost everything that the GOP establishment achieved during that time moved the needle leftward on domestic policy.

Whatever happens to the Trump candidacy—almost certainly nothing good—the insurrectionary mood inside the Republican Party will not easily be quieted. More than 40 percent of Republicans want illegal immigrants deported. The party’s best-funded candidates are committed to some kind of pathway to citizenship. More than a fifth of Republicans believe the wealthy wield too much political power.

The forces that have worked to render the GOP a minority party remain at work:

The Radicalization of the Baby-Boom Generation as It Enters Its Sixties

Through most of their life cycle, the people born between 1945 and 1960 expressed more liberal views than people born between 1930 and 1945. That abruptly changed in 2007-2008, as the boomers aged, the economy crashed, and Barack Obama was elected president. The boomers, a cohort more than 70 percent white, face retirement at a time when there don’t seem sufficient public resources for everyone—and under an administration that seems to regard non-poor retirees as a group to be redistributed from, not to.

The Assertiveness of the GOP’s Wealthy Donor Class

Limits on political giving have vanished as potential givers have amassed unprecedented wealth. Those givers differ on almost every imaginable issue from non-givers in their party. Unsurprisingly, the givers tend to get their way most of the time. Unsurprisingly, the non-givers resent it.

The Emergence of a Conservative Entertainment Complex

The entertainment complex appeals to a very small slice of the country—but it can make or break political careers within a larger Republican party. The only counterweight against it is the power of huge money from a narrow class of mega-donors.

After the Fox debate, I received an email from an old friend who advises one of the Republican Party’s very largest donors. I quote an extract with his permission:

This is the first time I've ever done anything but throw cold water on this idea, but I think the Republican Party is about to split.

The establishment's utter failure to even consider what Trump's rise means, much less how the Republican Party must accommodate Trump supporters rather than the other way around, means a split. And a good thing, too.

I have never voted anything other than straight-ticket Republican ticket in my life, nor ever considered doing so. But I think I'd be happy to cast one for Trump as a protest vote.

But, but, but … I wanted to say to my friend, you and your boss are the Republican establishment, or at least two of its very most important members! If we’ve reached the point where even the establishment hates the establishment, the mood is dangerous indeed.