The folks at Wonk Wire noted that each candidate (or desired non-candidate, e.g., Warren) has a Twitter account.
And so they analyzed those Twitter feeds and compared them to the "average" Twitter user. Who is, frankly, a Twit. Zero on this graph should not be taken as representing the average American; having said that, this chart ranks many of the important political figures based on their Twitter feeds.
For some reason I can't load the image, but you can find it at the link above.
Hillary is as far to the left of the line as the Drudge report is to the right. Senator Sanders is more than twice as far left of the line. Neither Hillary nor the President is as liberal as the typical Democrat in Congress; the typical Republican in Congress is about as conservative as Rush Limbaugh, with Ted Cruz winning the contest as the most conservative person on the chart.