The crisis in the Republican Party is even worse than it looks
1) They think he will lose badly to Hillary Clinton, perhaps so badly that Republicans lose control of both houses of Congress.
2) They are afraid he will damage the brand of the Republican Party, making it harder to win future elections.
3) They believe he lacks the temperament and character to serve as president.
These are all good reasons to be alarmed. But there is also a fourth reason for alarm that is perhaps the most alarming of all for conservatives:
His nomination could signal the death of orthodox conservatism as one of the two main forces in American public policy, since he is running away with the nomination despite being exposed as a non-conservative.
Trump is the candidate who finally figured out how to exploit the fact that much of the Republican voter base does not share the policy preferences of the Republican donor class, and that it is therefore possible to win the nomination without being saddled with their unpopular policy preferences.
He will not be the last candidate to understand this.
Future candidates will seek to rebuild Trump's coalition, and they will follow in his footsteps by opposing free trade, promising to protect entitlements from cuts, questioning the value of America's commitment to military alliances, and shrugging at social changes like the growing acceptance of transgenderism.
All three of the supposed "legs" of the Republican coalition stool - libertarian economics, social conservatism, and militarism - are at risk from Trump and the populist-imitator candidates he will spawn.
But wait, it gets worse.
It is easy to find examples of parties where ideologically orthodox members felt sold out by moderate leaders who softened party platforms. (Think of Tony Blair in Britain, or Dwight Eisenhower in the United States.)
But at least those moderate leaders tend to be broadly popular with the public, and to win elections, allowing those ideologically orthodox party members to get half a loaf in the form of implementation of a watered-down version of a party platform.
Donald Trump has somehow found a way to throw away the ideologically extreme ideas that orthodox conservatives cared about while actually making the party less popular. His nomination is a recipe for conservatives to sell out and lose anyway.
There is a missed opportunity for the Republican Party hiding somewhere within this trainwreck. Non-white voters are much more likely than white voters to tell pollsters they favor a larger government providing more services, so some version of the Trumpist economic agenda should actually help Republicans do better with more diverse voters, who have long been turned off by Republican anti-government rhetoric.
Because Trump has swapped out calls for Social Security privatization for overt appeals to racism, he won't be able to do that. But maybe - maybe - some future Trump imitator could find a way to keep the broadly popular parts of his platform while dropping the ones that have caused him to rack up the highest "very unfavorable" ratings of any party nominee since the start of the data in 1980.
But do not hold your breath for any faction of the Republican Party to take that lesson from their impending, devastating loss. Instead, three different factions of will each have their own story of why Republicans lost the 2016 election, each of them wrong.
Ted Cruz and his allies will say the loss was the predictable result of failure to nominate a true conservative. Faced with two essentially similar candidates like Donald Trump and Hillary Clinton, conservatives chose to stay home. To win in 2020, they will say, Republicans must abandon moderation and the desire for "deals" and nominate a stalwart, no-compromise conservative like Cruz.
Establishment Republicans will say the problem is that the party let the clowns took over, and must return power to the adults in the room like Jeb Bush and Marco Rubio, instead of toxic candidates like Trump and Cruz. They will not address the problem that orthodox Republican policy prescriptions are unconvincing even to voters in the Republican primary, let alone the general electorate.
Trump and his fans will say the Republican establishment sabotaged Trump by withholding their support, hoping they could quash his insurgency by manufacturing a wide loss to Hillary Clinton. They will not go away quietly.
This campaign has been compared to a number of television shows, including "Veep." But maybe the best comparison is "Seinfeld." After the Republicans lose, there will be no hugging and no learning. And that means the 2020 nominating campaign could be another circular firing squad similar to the one we are witnessing now.
You had better stock up on popcorn.