Great insights Caren and thank you for broaching a potentially delicate subject. Tucker Carlson's entire paycheck depends on the replacement theory, which goes something like"Democrats keep importing immigrants to fill the ranks of blue voters, etc etc etc".
Statistics clearly show that not all immigrants are naturally sympathetic to the blue tent. Each group has its reasons. Latinos are not pro-choice and are not very LGBT-friendly. They're used to tough politicians and near-dictator style leaders and they don't understand welfare states. Eastern european immigrants are still in post-communism whiplash and are culturally swung-right, which goes hand in hand with their unenlightened anti-ethnic sentiment.
I don't know why so many DNC intellectuals believe in the blueness of immigrants. This is exacerbated by the Bernie / Warren camps who have filled their airtime with talk of helping only the poorest and most needy - the unemployed, the Central-American migrants, etc. When small business owners hear this and nothing that helps them, they will wander over to the red tent.
You nailed with Biden's infrastructure plan and expansion agenda: this will fuel a giant middle class revival and will rescue tens of millions of voters back from red tent land to blue. Tucker can't stem this tide.