Population density drives leftism. As people live closer together, more government and rules are required. American freedom goes out the window. So yes, immigrants drive bigger government, but indirectly. There's no major genetic disposition for leftism. It's how tightly people are packed in. Many immigrants come from high density cities and move to high density cities.
Cities used to have optimum economies of scale but new technology has been pushing the optimum point many miles out from the city centers. Due to the growing federal government, NoVa is over-densely populated now. At some point though people come to their senses and move away. The massive immigrant pipeline is used to fill the cities back up so they aren't forced into immediate bankruptcy.
Everything changes constantly, but thankfully humans are not plant life and can move. It's much easier to move to where you like than to force millions of people to move for you.
I dont see how the Right can survive. Even if every illegal were deported tomorrow, the legal immigrants (and their kids) who vote (whether from India, China, Colombia, or Egypt) will gravitate to the larger metros and continue to be mostly Dems. Meanwhile, third and second tier metros, to say nothing of rural areas, are stagnant or dying. Meanwhile, white suburbanites, and especially white suburban women, are not buying what is being sold.
Florida is being helped for now by all the boomers moving from other states, but that generation didnt exactly replace itself well.