"Death of the GOP"

Supposedly Donald Trump winning the nomination has DESTROYED/EVISCERATED/MELTDOWNED the Republican Party forever and ever.  Except that no, it totally hasn't. Trump losing to Hillary Clinton should work out fine for them. The party will certainly still control the US House of Representatives. They might even hang on to the Senate.

More importantly, they will definitely continue to dominate most states.

How big is the GOP advantage in state legislatures? Well, they control about 7 out of every 10 chambers, and when you combine that dominance with their 31 governors, they have full control of 21 out of 50 state governments — compared with just seven for Democrats.

They will be fine. They will go right back to winning local elections by pretending they are the righteous victims of an unpopular President. It's what's worked for them this entire decade.