Trouble is that if anyone dissents from the idea (liberalism), they're immediately branded "un-American" by the high-priests of the American idea.
washingtonpost.com/opinions/when-…
nytimes.com/2019/07/26/opi…
newideal.aynrand.org/why-economic-n…
Maybe a church can afford to kick out heretics who don't accept its creed.
But a nation has to unite in times of trouble, acting on a mutual loyalty that transcends disagreements about "the idea."
Instead of loyalty to one's fellow nationals, they propose ideological rigidity.
I don't know. But if you want to put an end to the American nation, the best way to do it is to say that those who don't agree with you are "un-American."
You've got to stop driving people away and driving them out. You've got to embrace your neighbor as a brother national even if you disagree.