Well, he better start "doing " it now, because after 2010 he's going to be staring at a Republican Congress, pretty much.
That really is the only thing that could stop him — having messed up so bad that congress flips. But he already has a plan to counter act the people rising up to stop him:
For 2010: Passing a law allowing felons to vote
For 2012: Granting amnesty to illegals, giving them the right to vote