The 20s began after World War 1 and many US citizens believed that it was Wilson's progressive and liberal politics that made them join such a gruesome war that they didn't even have to participate in. They wanted to become more conservative and republicans easily won, however, the great depression came and since Hoover couldn't solve it, and he was a millionaire and wasn't very popular, people turned to those who could solve it. Since it was FDR who could do it, it was thanks to the events in the 20s and 30s that many of the policies that made America great after World War 2 were introduced.