Blatantly unconstitutional. The census is required to count the number of people in every state, not citizens (maybe a holdover from slavery? Idk).
Frankly, who gives a shit?
The Constitution has been dead for decades man, get with the times. Why should unrepentant criminals be given a voice in the system they scorn and reject? How is that fair? How is that right?
Constitutions are gentlemens' agreements. As such, they only work between gentlemen. Or put another way, they are artifacts of a high-trust society. Have you ever printed out the Constitution as plain text? It's about twenty pages long—which is really all you need in order to lay down some agreed-upon ground rules between a high-trust group of gentlemen.
But as always, dealing with low-trust people under high-trust rules is a recipe for disaster. Leftism is inherently low-trust because it is a fanatical utopian cult—cult members consider it perfectly acceptable to lie and deceive in the name of the higher calling of bringing about the utopia that the cult believes in. Consider the Supreme Court decision on gay marriage. The decision turns on the idea that Congress actually legalized gay marriage in 1868 when it passed the 14th Amendment, and it's just that nobody noticed it for the next 150 years or so. Do you
really think Ruth Bader Ginsburg actually believes that? Of course not—the cult decided that it was time for gay marriage, and as a high-powered cultist, she found a way to make it happen. It doesn't matter that it involved what was essentially telling a bald-faced lie. What matters to the cult is not such trifling lies, but the higher truth of the cult's ideals.
This is why treating the Constitution overly reverently is a very bad idea. We lose sight of the fact that a constitution exists to protect a civilization, not the other way around. Low-trust sophists have figured out the cracks in what was only ever intended to be a high-trust gentlemen's agreement in the first place, and have made it say whatever they want it to say (this is why the Supreme Court is so important to them: the unlimited power to "interpret" the Constitution is functionally identical to the unlimited power to rewrite it). Someone once said that Americans are foolish enough that they're willing to see a civilization destroyed for the sake of a constitution, and it appears for now that they are. Of course, that gets things exactly backwards—if your only concern is whether something is "Constitutional," you're the civic equivalent of a mother letting her child bleed out after a car wreck because she doesn't want to cut through her nice seat belts in order to free him. At best, a constitution is just a tool used in furtherance of the purpose of preserving your civilization, but we've forgotten that as a people.
Whatever it once was, the Constitution has become a stone around our necks, dragging us to the bottom to drown. Seeing this happen with my own eyes has convinced me that written constitutions are too likely to become an object of excessive veneration among the people, and thus are more trouble than they're worth.