Uncontrolled illegal immigration, across a chaotic and completely unregulated Southern border, is the designed intention of Democrat policy. The Democrat party believes it gains an electoral advantage by having the largest possible dependent underclass, and a sure-fire way to expand the dependent underclass is to allow anyone to walk across the Southern border and stay, on any pretense or on no pretense at all.

This is happening because the Democrat party wants it to happen. The tradition of immigration into the US was built at a time when there was little to no publicly-funded social safety net and when the immigrants had little choice but to assimilate into American culture. With public debt at the Federal level alone (not mentioning State and Local) roughly equivalent to all the money in the world, and with identity politics valuing any non-American national identity more than an American identity, the US can afford neither fiscally nor culturally to continue Democrat policies on immigration.