I'm going to assume that you're talking 2024 and later.

Building a new party sounds great, but is in reality extremely difficult. All you need to do is look at the laundry list of useless third parties that have all the national appeal of wet cardboard.

"But Trump is the President," you say. "It would be different if it was started by him."

Maybe a little bit, but the most likely outcome would be that The Trump Party siphons off a sizable chunk of the Republican Party, and a subset of Democrats, leaving both the GOP and Trump Party as ineffective at the national level. Sure, that would teach Romney and The $5 Project a lesson, but it would also mean that the Democrats have an even weaker opponent at the national level. It would take many years, perhaps decades, for the Trump Party to fully replace the GOP.

The other uncomfortable truth is that Trump is in his mid 70s. By the time 2024 rolls around, he will be approaching 80. Maybe he has another 15 years on this spinning clown rock, maybe 20, but whatever new party that comes along would need new leadership, which brings us back to the real problem facing the GOP in the first place.

The GOP lacks proper leadership, but has the name recognition, the infrastructure, and the money to be successful, which a new party would have to start from scratch to build. That's time that we don't have, especially when the backbone of the party would consist of busy families and people with regular jobs (i.e. not the jobless professional grifters and agitators that populate a movement like blm).

Party realignment has happened many times throughout history. You wouldn't abandon or tear down an entire house when it needs renovations, so don't tear down the party when it still offers something.