One has to admire your bravery and honesty in revealing your true name in this forum, mr Coward; I personally prefer to hide behind a pseudonym, because I am scared that anybody finds out.
So, as you say, your guy seems to have it all his way; of course that also means that later, when his policies turn out to be major disasters, you can't hide behind "Oh, but the senate/house/... opposed us all the way, so of course it didn't work out." And unless he turns out to be a truly astoundingly brilliant leader, he will face growing, popular opposition - starting from 50%, in fact - and popular opposition is not as easily controlled as the senate and the house.
Here is what I think is likely to happen: He'll start out in typical, bumbling style, maybe initially he will have the support of the Republicans, but fairly soon the deep resentment that was all too visible during the primaries, will come to the surface again, and they will start opposing him in growing numbers. The popular opposition will spread from the current 50% to something much higher, because a lot of the people who voted for him don't like him much, and a lot of the angry people who voted for him, did so because they hope against hope that he will make things better - when he fails, as he must, they will turn against him with fury. And then come the midterm elections, where he loses the senate and the house.
Meanwhile, the Democrats will have 4 years in relative peace, where they have the chance to do some serious rethinking of their whole setup, and can work on reconnecting with the voters. They won't be in power anywhere, and will therefore not get their name attached to unpopular policies that come out of government, but they will still be under pressure from their electorate to improve their ways, so it is conceivable that they will actually do so.
So, all in all, it will be worth watching, certainly. Where the whining will come from, though - we'll see, won't we?