Let's clear something up, I am far from a "leftist." That's some cheap term coined in the past 20 years by scared Republicans losing their power. Both sides play on identity politics. Both sides feed fear to their base. The left tends to play the victim card and convince its followers that their problems are due to external forces. They import immigrants for their votes, make no mistake. Confusing children as to their gender, allowing unfettered abortion as a form of extreme birth control, and blending us all into some type of rainbow coalition, kumbaya nation is unrealistic and unsustainable.
On the flip side, the far right ideology is unsustainable as well. There exists a certain fraction of the population in America that wakes up scared every day. Scared that they are losing their country to brown and black people that don't look, speak, or think like them. Such was the sentiment against the Irish, Italians, and Jews. America has always found someone new to be afraid of. Flavor of the month.
Thankfully millions of Americans are moderate. They lean conservative on some things, liberal on others. They have the ability to examine a situation and form their belief system in a center left or center right position. That's sustainable, in the end.