You do realize that with many things Obama tried to do he was blocked by Congress and through other means at almost every step of the way, right? From things like immigration reform to the affordable care act his policies were stalled, nitpicked, and transformed far from what his vision was. To the point of shutting the federal government down even. I think it's safe to say that things would be very different if the Republican Congress had made more efforts to work with him rather than just fighting him (and then ironically cash in on people's frustration with the governments ineptness to pass legislation.)

Look at the Supreme Court seat for example. He nominated a judge who was well liked on both sides of the aisle - he truly tried to make a compromise and not appoint someone who the Republicans would view as "ulral liberal" and what did they do? They refused his nomination and cited total nonsense as to the reason's why.