Rank each decade from the 1910s from most conservative to most liberal

[Orser67]

1920s
1980s
1990s
2000s
1970s
2010s
1940s
1910s
1950s
1960s
1930s

The 1920s and 1980s were the two big "conservative retrenchment" decades in which liberal reforms were rolled back. Conservatives had the upper hand for most of the 1990s and 2000s and liberals just did their best to slow conservative momentum until the financial crisis broke the Republican Party for a few years. The 1970s were a transition decade in which the liberal consensus was still intact but conservatives were beginning to win the national conversation. The 2010s are a similarly split decade in which liberalism has definitely made a comeback (especially in the Democratic Party) and scored some huge victories in Obamacare and Obergefell, but a very strong conservative plurality remains. The 1910s are often overlooked for their impact on progressivism, but the decade saw the implementation of the income tax, the Clayton Anti-Trust Act, the Federal Reserve, and the FTC. The 1930s through 1960s were a period in which liberalism dominated, and while a backlash started in the 1960's, that decade also saw the second largest expansion of government with the Great Society. Conservatives were largely able to check any further liberal moves in the 1940s despite two liberal presidents, whereas the 1950s saw the beginning of the Warren Court's judicial revolution. I really think that the 1930's has to be first; that decade changed government as we know it.