President Trump has been denounced by multiple members of Congress, by the CEOs of leading American businesses like Apple, Google, and GE, by the Pope, by superstars, and by masses of people across the United States. Multiple judges have ruled that his Muslim travel ban is illegal. The rest have denounced it as a threat to American security, as inhumane, as unfair, and as counter to Christian values.
Home grown terrorists have burned down a mosque in Texas with his encouragement, and the malaise poured over the border to the mass shooting at a mosque in Quebec. This happened, in no small part, because Trump encouraged the perpetrators.
Republicans lost seats in both the House and the Senate in 2016, despite Trump's electoral college win. Trump's approval ratings at the start of his first term are lower than any President in history and falling fast. Republican officer holders are starting to smell blood in the water and to realize that if they tow Trump's line that they will go down with him in two years. Trump lacks majority support for his travel ban in either the House or the Senate due to public GOP defections.
The Republican establishment has never liked Trump, but, because they failed to agree on an alternative early enough on, they were stuck with him and backed him in the election. But, they have no loyalty to this outsider who clearly doesn't trust them either and doesn't play by the political rules.
It isn't at all unprecedented for serious failures while in office to bring a party from a thin majority to virtually being wiped off the political map in a single election. It has happened in Canada. It has happened in the U.K. It has happened in Greece. And, it can happen just as dramatically in the United States is the Republicans don't get this dumpster fire under control and fast.
Many people who voted for Trump in 2016 already regret their decision. Almost nobody who voted for Clinton thinks that they made the wrong choice.
If Trump continues to try to implement abhorrent policies that hurt ordinary people, he will fan the flames of the resistance against him and take his entire political party and movement down with him. And, right now, that looks like exactly where we are headed.