It's simple. A massively Republican Congress can be scape-goated, the source of all woes. Oh, and since his plan is to completely destabilize the American political and economic system, having two branches duking it out in high political drama all the time will have enough of the population cooing for benevolent dictatorship before too long. Especially with a compliant media, which will start to wonder whether indeed a system of divided government can POSSIBLY work anymore.
It doesn't take a lot of imagination when your dealing with a radical ideologue and all-around dolt to see through the obvious.
Good points.