They certainly weren't leftist but they were all (except for roosevelt) "American consensus" style new-dealers, and except for many foreign policy & culture issues were to the left of Bernie economically, because that's where the country was when they were in power. The country shifted massively to the right between LBJ and Reagan, although it realigned to be much more progressive on race during that period. Actually these things are quite interlinked - there's a book called Before the Storm: Barry Goldwater and the Unmaking of the American Consensus that covers this pretty well - how Republicans went from being the party of Lincoln and political home of black people to shrugging off that legacy and becoming the party of unbelievably frothy white reaction to basic civil rights for black people.
They certainly weren't leftist but they were all (except for roosevelt) "American consensus" style new-dealers, and except for many foreign policy & culture issues were to the left of Bernie economically, because that's where the country was when they were in power. The country shifted massively to the right between LBJ and Reagan, although it realigned to be much more progressive on race during that period. Actually these things are quite interlinked - there's a book called Before the Storm: Barry Goldwater and the Unmaking of the American Consensus that covers this pretty well - how Republicans went from being the party of Lincoln and political home of black people to shrugging off that legacy and becoming the party of unbelievably frothy white reaction to basic civil rights for black people.