It wasn’t the 20th Century; it was 1868. That’s when States’ Rights officially died, and when the 10th Amendment became subordinate to the Ninth.
We can decry this result, but we can’t pretend it came completely out of the ether. Once unenumerated rights became more important than the ability of states to implement their own policy, the groundwork was laid for precisely this.
A lot of folks smarter than me don't agree that the whole package of silly was contained in the 14th Amendment, partly because if facially was about "servitude" and nothing else. But on a more practical note, none of that Brennan cr@p happened in 1868, or 1878, or . . . because it would have made no sense to anyone. It happened when it did—I guess it began with Frankfurter—because it was connected to the world socialist movement that was being spread about in the 1890s and following. So screw it. It had nothing to do with the Constitution, before or after 1868.
This may be where the money and guns come in. But the point is, they're going to come in one way or the other. When you fold your cards on subsidiarity (States' Rights being an example), you have tyranny. That's not a goal. That's an obstacle.