Precedent for New Deal decisions can be traced directly back to the Mann Act, which included all-encompassing language like "to aid or assist in obtaining trans

Precedent for New Deal decisions can be traced directly back to the Mann Act, which included all-encompassing language like "to aid or assist in obtaining transportation" and "to induce, entice, or compel". See https://archive.org/stream/283075-the-mann-act-1910/283075-the-mann-act-1910_djvu.txt https://archive.org/stream/283075-the-mann-act-1910/283075-t... Actually, IIRC you can go back further to the fugitive slave laws to find precedent where activities only incidental to interstate commerce were deemed to be reachable by Federal powers. I say this not to defend it, but to point out that the history is complicated. And that there's not a simple liberal vs conservative dichotomy. Historically conservatives have supported expansive morality and pro-business laws and liberals expansive social programs and protections going back a century before the New Deal, and each used precedent set by the other. (Small 'c' conservative and small 'l' liberal because linkages to particular parties and political interests gets messy quickly, especially the wider the window of time.)