Honestly, it seems to vacillate depending on who's in charge, what with the Left bashing Bush one moment and heaping praise upon Obama the next — despite Obama taking the warmongering, mass surveillance, and banker bailouts to new levels, most of which they barely acknowledge at best.
Not to mention how opinions vary based on how far left a given Democrat is, what with an Average Joe neoliberal shaking his head at Trump and having lukewarm feelings towards Biden, while the pink-haired college activists with "Bernie 2020!" bumper stickers on their cars despise him as a "secret right-winger" or something to that effect.