He was a terrible President, despite some positives like the Marshall Plan.
It is truly amazing that the Dems have been able to rehabilitate him posthumously."
I would give Truman more credit -- as a Democrat, he falls into the same category as, say, JF Kennedy meaning: as good as we could ever hope for.
He gets credit for a list of accomplishments, including ending WWII, recognizing Israel, recognizing the Soviet Cold War threat (Truman doctrine), integrating the US military, saving Greece from Communism.
Of course, he was far from ideal, and his "police action" in Korea set the unfortunate example for virtually every US "no win" war since.
But the biggest thing to remember about Truman is that his state of Missouri is today between 2/3 and 3/4 Republican, where even Democrats like Claire McCaskill have to pretend they are semi-conservative Republican-lites.
Yes, Truman's old Jackson County (Kansas City) stomping grounds are now solid Democrat, but state-wide, Truman today would have to run as a Republican:
Senator Harry Truman, 1934:
Today's MO 5th district (Jackson Country) US Representative, Emanuel Cleaver: