Holy cow, the Trump administration is off to a really awful start. I knew London oddsmakers gave him only a 50% chance of serving at least 4 years, but I never thought he'd bring on a constitutional crisis so quickly.
As awful as the situation with the temporary ban on immigrants from some majority-Muslim countries, I think what we're seeing here is the break up of the establishment GOP and Trump coalition. The GOP establishment was always distrustful of Trump, but they thought they a) had no choice but to fall in line because of Trump's popularity among their base; and b) thought they could use him to get some of their pet laws passed--especially cutting taxes on the wealthy and dismantling social programs.
But with his flurry of poorly-thought-out executive orders, Trump has thrown the government into chaos. Spontaneous demonstrations have erupted all over the country. The courts have ruled against him, at least temporarily, and more lawsuits from individuals, organizations and states are in the works. Some GOP congresscritters have criticized the Muslim ban, and even Dick Cheney says it "goes against everything we stand for. "
If our democracy survives, I think the GOP will eventually rue the day Trump was elected. Or maybe they do already. He has only exacerbated splits in the party. He will unfortunately do a lot of damage to the country and world before he is eventually stopped, either by impeachment, the 25th amendment, or the 2020 elections.