Allowing non-citizens to vote? Lol. Wow. No, they're not.
Democrats aren't the ones closing voting precincts in non-white / poor areas, making it illegal to hand out water / make people more comfortable while they're waiting 4 hours to vote (because of all the closures in those areas) and gerry mandering the **** out of voting areas to make sure they win with the minority vote. Yes, Democrats want to make it easy for people to vote, but that's about it.
re: the census. No, it doesn't. It gives them more idea of where to spend money / social services / schools / roads / whatever. The Senate is capped at 2 people per state and the House also has a total cap of 435 reps that hasn't changed since 1929 . Rural areas are actually way over-represented per capita due to this and add in the aforementioned gerry mandering and you've got your self a minority in charge. Nothing is being diluted since it's the same numbers of reps and the reps are the ones that do the actual "voting" on what gets done.
There is no destruction going on. America was founded on immigrants and the vast majority of "families" have been in this country less than about 100-120 years. The majority of immigrants just want a job and to live the American dream. They, for the most part, work their asses off doing jobs no "American" (read: white person) will or wants to do for what corporate America is willing to pay.
For the most part you're mad at a made-up boogeyman so you don't notice you're getting absolutely reamed by the 1% and/or think you will be one one day.