What Reagan did was a massive fuck-up but I can understand the theory behind it and there was still a chance to course correct. But the 2000s were when things really tipped. Bush and the neocons ran on deporting illegals, but did nothing as I personally saw areas that were still majority white tip into majority spic. My schools were flooded with kids who had illegal grandparents, parents, or themselves were illegal, and nothing was done. I sat through the first Trump administration where all he talked about was deporting criminals, while leaving anchor-baby popping and wage depressing "regular" illegals alone, when he should have been getting rid of the "regular" illegals all along.
Trump has been better than Bush, but only because Bush & co did literally nothing, on purpose, because their corporate buddies didn't want them to do anything.