The problem I see for the Repubs is that their ideology is in direct contrast with the changing demographics of the country.
The Repub ideology is basically Plutocratic in nature, which lends itself to being exclusionary rather than inclusionary.
It's hard or near impossible to change an ideology based on minority rule while still needing the votes of a majority in opposition to actually exist as a political entity.
We've already seen how the Repubs tried to overcome this obstacle using among other more subtle ploys, voter disenfranchisement, voter suppression and gerrymandering being used to accomplish their goal of minority rule.
And we've also seen how the Repubs employed minority rule in the Senate via filibustering, etc. So it seems to me this hard and fixed track they've laid for themselves is diamterically at odds with establishing a big tent philosophy akin to the Dems, which, for the Dems, is practically intrinsic in their own ideological principles.
Two parties vying for a changing demographic that inherently favors the Dems is something the Repubs will need witchcraft and god-like powers of deception to overcome. Not saying it's impossible seeing as if deception and misrepresenting themselves have been powerful and well-employed tools that they've used with striking effectiveness in the past.
I do think the Repubs have learned from this past election cycle that they can't be as honest, forthright and, well.....blatant in their ideological quest for minority rule.