FDR was a Liberal Democrat, once considered a traitor to his class he was in fact its salvation. He saved the United States from a possible revolution when the unemployment rates in cities like Toledo, Ohio stood at 80%. At that time there was no Social Security, no disability, no unemployment insurance, no food stamps and no aide to mothers with dependent children. In his Second Bill of Rights, Franklin Roosevelt declared healthcare a right due all Americans
After Roosevelt's death Harry Truman assumed the position. Truman was also a Liberal Democrat. As a Senator, Truman was one of the most frightening men in Washington"to defense contractors. During World War II he rooted out over a billion dollars in fraud and corruption sending one Army general to prison. But Truman had read reports about the large numbers of men unfit for military duty because of poor health, bad teeth and scurvy. Harry Truman proposed Medicare for all in 1948.
Truman was replaced by Dwight Eisenhower. Eisenhower was a moderate Republican. In truth, Eisenhower was being lobbied as a Presidential candidate by both parties. As leader of the Allied Nations Eisenhower was tremendous as a President his administration was of a caretaker variety. He warned us about the military Industrial complex and then retired to continue his golfing on a private basis. My father used to joke, don't blame Eisenhower, he didn't do anything.
John Kennedy was a Conservative Democrat. Got that conservative. Harry Truman thought he was too young and too conservative. Kennedy brokered nuclear arms treaties with the Russians and launched the space program. He eliminated by executive order, Jim Crow discrimination in interstate transportation. No more Colored Waiting rooms and while he had his pen out, he signed an executive order outlawing discrimination in Federal lending. In his free time, he raised the minimum wage by 25% and he did it all in three years.