The president of the USA cannot really ram anything through without having both Congress and the Senate behind whatever it is that he is trying to do. Obama was not able to push much through in a positive direction (and what did get done, was watered down); Trump will not be able to push much of his absurdity through, either. Even if the USA elects a Republican Congress, I get the impression that most of Trump's own Republican party is not behind the policies that he advocates.
He will, however, be able to turn the US into a laughingstock of the rest of the world, and make a mess of international negotiations (be it trade, defense, refugees, or whatever). I can't see him making too many friends in the international community with some of the self-centered policies that he advocates.
Does the US government as a whole need a shake-up ... Yes. But not Trump's version of a shake-up.
I consider the alternatives to Trump - all of them - to be do-nothings.
Donald Trump = Rob Ford. Somehow we got through that.