Truman was of the era of Scoop Jackson, Estes Kefauver, and even Adlai Stevenson-men with whom you might have disagreed with but who you could respect because they had some measure of integrity. The weasles running the show today take all their cues from George McGovern and Jimmah Cahtah.
Truman did his best to keep conservative Democrats. Stevenson was charming but do we know if he would have used the IRS as JFK did to shut down conservative think tanks?
The argument that libs have that Stevenson lost was that his image was that he was a funny man. And that he was "too smart".
I would like to see more loyal opposition, but then again, look what they did to Moynihan