Excellent analysis, Kevin Donovan.
Even before Trump, the Republican Party has steered away from policy and, I would argue, politics. They have successfully cemented themselves into a party of opposition and are ill-equipped to govern.
As you point out, they have an enormous problem that can serve as a new beginning. It will take leadership which presently is sorely wanting. Some individuals need to emerge to form a NEW Republican Party, essentially.
The irony is that Republicans have constituencies in their lap to champion issues fundamental to American prosperity and security, which the Democrats would have difficulty with. A basic income for all Americans (a Milton Friedman notion) is an example of where they could be successful, and many others.
Many thanks. Best.