to 2017 Barack Hussein (D, IL)
2017-2021 Jon Huntsman (D, UT)
2021-??
I don't have the Party identification wrong on Huntsman; he will have left or been purged from the Republican Party. By 2018 the Republican Party will have gone the way of the Federalists and Whigs (or States' Rights at the absolute worst; in 1968 one of its few card-carrying members was James Earl Ray). By 2020 the Democratic Party is so unwieldy that it splits into a Social Democratic Party and a Christian Democratic Party as American politics become more ... European.
That's a good point. In most of European countries such people as Brownback, Bush, Coburn of Inhofe would be nothing more than a bunch of fringe politicians without any significance and probably out of any parliament. But in U.S. they are, scary to say, in some way mainstream.
Well, even in Poland in worst case guys like Bush, Coburn or DeMint woule be members of some very fringe, minor party as present League of Polish Families 
The same applies to people like Bernie Sanders, Dennis Kucinich or Barbara Boxer. According to U.S. standarts they are "far-left", but in Europe they'd regular social democrats.
Hmmm... and the US is the most economically successful country at the moment and, if trends continue, will recover from this recession faster than many European countries.
Anyway, the Republicans aren't going anywhere. There's a reason they've survived 150 years.
