I'll tell you why. We are not yet strong enough for a frontal assault, politically speaking. The next two years is to showcase why divided Gov't doesn't work, and why the electorate needs to elect a Republican President in 2016.
Once we own all three branches, we then begin to take apart the beast.
Obama wants to prvoke a Constitional Crisis to get the Right to react, so he can claim "Racisim" and bring out his base in 2016 - don't take the bait ...
Do you think we'll get enough non-corrupt in there at a single point in time to do so?