Not sure what 'leftish' means but I think some share late 60s/early 70s lineage with some centrist Dems: so-called 'New Politics' of upper-middle strata intellectuals and professionals for whom civil rights and antiwar movements were formative experiences (or at least had some resonance)...
Re. Bradley, he was one of first Dems in early 80s to call for 'tax reform', recall likes of Arthur Schlesinger blasting him for championing 1986 reduction of tax brackets to only 3 rates and lecturing him on principle of progressive taxation...of course, Bradley did address 'Live Aid' concert so that counts for something, eh... Michael Hoover