Well I was never actually a registered Democrat, mostly just an apathetic independent, but if pressed to have an opinion either way I was pretty out there on the left (and in some ways I still am), and I would categorically support Dems over Republicans, though I didn't like politics in general. So while I don't have any stats to say whether the "Blue Republican" phenomenon (Ugh, while I adore the concept, that is not a very snappy moniker) is widespread or exaggerated I do know they exist, for what it's worth.