President Donald Trump is sitting atop a party ready to pull apart at the seams. The figure who was supposed to assemble a governing coalition that included both populists and supply-siders; college-educated whites with older, working-class whites; and nationalists with pro-business Republicans has instead revealed the schism between each of these pairs, increasing the likelihood of a 2018 election debacle and a failure of the Trumpian experiment.

Running as a populist, Trump promised health care to cover everyone, no cuts to any entitlements (Medicaid, Medicare, Social Security), repeal of Dodd-Frank and middle-class tax cuts that don't shovel more money to the rich. He has done the exact opposite. The American Health Care Act is a tax giveaway to the rich that does not cover everyone and cuts Medicaid. His tax plan and budget plan look like a parody of a right-wing agenda.

There are two problems here. First, his base is getting hit, not protected. And second, the right-wing agenda is overwhelmingly unpopular with the country as a whole. It's not like Trump was a policy wonk, so when he filled his Cabinet and senior staff with right-wing extremists, he wound up with an agenda that he ran against. Trump, of course, doesn't care what is in any legislation, but his base might, and the right wing that thought he'd deliver on their wish lists may be depressed and disappointed.

Then there is the class split within the GOP. The GOP has had downscale voters since the term "Reagan Democrats" was coined, in addition to upscale suburbanites who like lower taxes, efficient government, and law and order. These sides were held together by mutual disdain for Democrats, by social conservatism and by a preference for a strong national security. Trump has managed to accentuate the differences.

Finally, we see the nationalist/business split play out. The latter thought they'd get tax relief, smaller government and a more respected foreign policy profile. They want policies that favor globalization (trade, immigration, international cooperation on climate change), but Trump has gone in the opposite direction, mainly pleasing nationalists who think America is getting ripped off. These nationalists want Trump to tell off the world. 

When Hillary Clinton was on the other side, the disparate elements could hang together, especially if Trump was going to do a little of what everyone wanted. Now that he has accomplished so little and essentially dropped the populist agenda in favor of an unpopular, right-wing script, it is far from clear everyone can live together — or will be excited enough about the marriage of convenience to turn out in 2018, or even 2020.

Democrats have figured this out, too — simultaneously reminding working-class voters that Trump tricked them (and is now just another guy giving tax cuts to the rich) and reminding upscale Republicans and business interests how destabilizing, not to mention embarrassing, Trump is. Remember that the 2016 election was very, very close, so Democrats need only peel off some of one or both groups to make headway, particular if they keep the Democratic base energized. As for energizing Democrats, there is no one better than Trump at keeping them spitting mad and looking to vote out whoever has an "R" next to his name.

— Jennifer Rubin writes the Right Turn blog for The Washington Post, offering reported opinion from a conservative perspective.