Though I share your pessimistic outlook, one factor that could delay permanent Democrat rule is that as the Democrat party becomes ever more explicitly anti-white, the percentage of white voters going Republican ought to increase.
Yes, you make a good point, and I agree.
Nationally, white voters have floated between 55% and 60% Republican for the last sixty years.
That percentage increased to the low 60s for Nixon in 1972, and for Reagan in 1984.
If white voters vote like they did in ‘72 and ‘84, and like they did in 1994 for the Newt Gingrich Congressional landslide, we still have a fighting chance.
But long term, if we do not stop massive legal immigration immediately, the game is over for Conservatives.