The biggest problem the GOP faces is that it has proven itself to be eminently untrustworthy when it comes to fulfilling its campaign promises. I don’t see that changing anytime soon.
I’d like to see a new sort of approach: a party with a short, focused platform (no abortion, no tax increases, whatever) and the party will support and fund ONLY those candidates who PERFECTLY adhere to the platform. Any back-stabbing, deal-making, or dishonesty means you get ousted from the party and you get no support. Fulfilling campaign promises and adhering to principles ought to mean something.
In the Senate the biggest problem is that McConnell hand picks a RINO candidate in the primaries. The RINO gets a lot more funding compared to the conservatives, because of McConnell’s PAC and corporate money. And there’s usually more than one conservative candidate, splitting the vote. There’s never more than one RINO candidate because they only run with McConnell’s blessing.
The only way to stop this process is for conservatives to unite behind a single well funded conservative candidate. Trump can help that happen by endorsing a candidate, and through his PAC.