I'm a little hesitant to be fully trustworthy of Pro-Democrat polling numbers from "Democracycorps.com"; kinda like how I'd sort of give the AEI polling numbers a grain of salt.
As for the Clinton / Obama "who is more progressive" fight - part of the reason there are rose colored goggles (and frankly, a lot of cherry picked bullshit, I adore you Hill-GAF, but gonna call out the circlejerk on this one) on Clinton's "progressiveness" in 2016 is because currently
social values are the leading push for progressive values. Which wasn't the case in 2008.
In 2008; it was primarily foreign policy / Iraq War that was driving progressive politics - in which Clinton is very hawkish. Iraq / Afghanistan haven't been a big political factor since before even the 2012 election. You can't compare what is primarily driving progressive (and, hell, all) politics in 2016 (identity) with what was driving 2008 (foreign policy) and then apply 2016 standards in 2008 and declare retroactive victory.