I wouldn’t repeal the 20th century, but I would repeal any growth of FedGov beyond the enumerated powers. I’d like to start with a $1T cut in FedGov spread over four years ($400B, $300B, $200B and then $100B). Also completely eliminate all efforts to redistribute wealth, and then start identifying other potential areas to cut.
There’s areason why Congres has far exceeded the enumerated powers: the wealthy in this country want them to. After the Civil Warm, the powers of the Supreme Court increased greatly because the new rich needed it to stop the states from regulating their activities. To be sure, they were right that much of the regulation slowed industrial expansion. Nonetheless it increased the role of the Federal Government significantly.