Regardless of who was in power, Johnson remained a critic. But Johnson liked and supported progressive Franklin Roosevelt, although he did not like some of FDR's positions. That dislike eventually became bitter opposition by the end of Roosevelt's first term. But at the start of that term, Johnson was offered the post of Secretary of the Interior, which he declined. He said, "I have lived so long in absolute independence that it is a very difficult thing for me to see myself a member of any group where I would discipline myself to the view of any one, or any few men."
For four years, Johnson voted for every New Deal program. But he feared these programs were giving the federal government, and the President, too much power. The final break came as a result of the Court Packing Plan in 1937. He also opposed FDR's foreign policy. Although he realized the evils of Hitler and Mussolini, he warned that in "fighting a European dictator, we would create one of our own."
After Pearl Harbor, even Johnson realized that isolationism was no longer possible. He loyally supported the American war effort. But he still opposed any organization of nations after the war. He was one of only six Senators to vote against a resolution calling for a post-war organization of nations. He was the only member of the Foreign Relations committee to cast a vote against the United Nations, and one of only three in the full Senate.