Don't be fooled by Trump's election. The GOP may look strong, but they really only won because they demonized Hillary and fooled Americans into thinking she was the enemy, and they had the help of Russia, the FBI, and a very flawed electoral system. The GOP is doomed, because they are out of touch, their President is terrible, and they're certainly going to get blamed for everything in the next few years.
I believe the G.O.P. has certainly made some bad mistakes over the last few elections and many would say that it is standing on its last leg. I believe one of their biggest problems was selecting Sarah Palin as a running mate for McCain which spoke a lot about the G.O.P.'s view on women. Secondly, in the last election they put a person up that was incapable of comprehending the majority of Americans problems. If they don't come up with a viable candidate this time I'm sure they will lose their footing entirely.
The problem with the G.O.P is it has gone so far to the right that is excludes people in the middle, and moderates. The tea party has taken over the party with their extreme social views, but they do not have the numbers to back this up. If the Tea Party agenda continues to be the face of the G.O.P. it will continue to sink.
While I consider myself to be somewhat conservative, I believe the GOP has far too many internal issues to remain a viable party. The party has developed a terrible reputation and is struggling to agree with itself on several key issues (especially same-sex marriage). I would love to see the GOP dissolve and make room for the Libertarian Party.
The reason the GOP is dying is because they have gotten so far away from the constitution and what really are American ideals, that people are beginning to feel alienated. They operate on fear and draconian principals most of the time. Compare the platform now to the one in the 50s. The 50s GOP was much more progressive and for the people.
No, this party has been around for a long time, and it is not going anywhere anytime soon. The politicians in this party are smart, and they will find a way to bounce the party back, and I would not be surprised if in a few years they are bigger than ever.