Hillary can deliver the Congress to the Democrats, then you can teabag her from the left and force her to sign laws to her left. That's all you should want out of a President if you are a progressive.
I think this is fair point -- the way to get a progressive President Hillary Clinton is to elect a progressive Congress -- admittedly a difficult assignment given the gerrymandering in U.S. House districts. But I consider judicial nominations a big deal and that is hugely impacted by the makeup of the U.S. Senate.
Back in 2008 many people were hoping that President Obama would be some liberal hero/magician once in the Oval Office. History and experience should make them more realistic.