A lot has shifted over time, but the default state of American politics has always been two dominant parties.
That said, I could absolutely see a scenario where an American centrist party forms, still solidly to the right of most Western democracy, but centrist by current local standards, which not only pulls in the non-MAGA Republicans but also moderate Democrats, blue collar Dems from purple states, and once it gains traction and wins a few races, massive support from corporations and lobbies.
They’d win landslide victories over both older parties, especially as progressives and leftists gained greater control of the Democratic party through the flight of the moderates to the new centrist party, which would in turn drive even more establishment Dems to the new party.
They could run on nothing more than “common sense compromise, unity, and moving beyond the partisan squabbling that has plagued the country for decades”, and be successful for at least 3 cycles before they even had to really take up any issues in earnest.
The deep South would stay red, the West cost, new York, and Illinois would stay blue, but I could see all of the mid Atlantic, Midwest, plains states, new England, and Southwest going for a viable centrist party.
For a long few years, national level politics would be absolute fucking chaos.
Fair point