The last really good Democrat president was Thomas Jefferson.
Actually a Democratic-Republican, in conversation usually republican, but ended in 1834. Not really a predecessor of either of todays partys of the same names. Democrat Party was founded by van Buren in the late 1820s, Jackson their first President followed by van Buren. Essentially split the Democratic Republican party into Democrat and National Republican parties.
Personally- I liked Truman as one of the best of the worst