Every now and then, one of the major parties goes off the track and forfeits an election, as in 1964 and 1972. This time, it is possible that the Republicans are the new Whigs, headed for a crackup, an oft-made comparison that historian Michael Holt recently examined in the Crystal Ball.
However, it’s just as possible, maybe probable, that the party would repair itself by 2020. Four years after the Goldwater debacle, the Republicans elected a president. Four years after the McGovern disaster, the Democrats elected a president. Odds are, there will be no need for a bugler playing taps for the GOP this time either. Somehow, though, Republicans will have to find ways to heal the deep rifts in their party, while becoming more mainstream and accommodating to this century’s American electorate. It will take far more than another “autopsy report” like the one in 2013 to accomplish this.
I think that view is strengthened incredibly by a 2018 midterm election that I expect will go just as badly for the Democrats as 2010 and 2014 did. Whatever gains the Dems make in 2016, say, six or seven Senate seats and 20 or so House seats will almost certainly be given right back and then some in 2018.
In the Senate, Democrats Heidi Heitkamp (ND), Joe Manchin (WV), Jon Tester (MT), Bill Nelson (FL), Joe Donnelly (IN), Sherrod Brown (OH), Tim Kaine (VA) and Tammy Baldwin (WI) would all have tough races, and that's before any retirements factor in.
The House, without Trump weighing them down, would probably end up back where it is now, with Republicans having close to or at the largest margin since the Hoover era, if not more. You thought Dems mailed it in and gave up on Obama in midterms, wait until 2018 and Clinton.
The counter to that is the GOP will somehow have to get their crap together in time to make a run at 2018, and I'm not 100% sure they'll be ready to go by then. The damage from Trump may be too deep to repair in two years.
But that's just back of the napkin stuff at this point. A lot could happen, and will, before the 2016 and 2018 elections that will change everything.