I was going to fight the first 3/4 of your post by pointing at how things were done in the U.S. for the last 8 years but then came your last two sentences. This is almost always how any political discussion goes and it's why most people don't like discussing politics. You will always have two (or more) sides firmly entrenched in their opinions and arguing about it with very little common ground in between.
I think this here is the biggest problem in the West nowdays, and not just the US, but also Europe in a slightly more plural way.
As an outsider, I can empathize with both sides here, because frankly there are some very valid argumens from both directions. However the onus to do some deep thinking here is NOT on the Rebublicans, but the Democrats. If everything was so great under Obama, how did you lose the House, Senate and the Presidency? For this to happen, you MUST have done something wrong. Pointing fingers at Trump will not help you, he's a known egomaniac and loose cannon, but it will not get you anywhere.
You should instead look at why have you alienated your voters. Is it some key politicians they don't like? Is it some thing the Obama Administration did or didn't do? Maybe some of the ideologies you're assosicated with go against common sense? Maybe some actions make you look hypocritical? Some groups you are associated with are too divisive? Maybe you shouldn't be promoting identity politics, as it's inherently divisive? JUST DO SOME THINKING DAMMIT.
Unfortunately, I don't see this happening, you are playing the victim card, like so many of the identity groups you are associated with. It's a losing hand.