As long as they want. People hate congress, but they love their congressmen and women. As demonstrated by Obama's continuation of so many of W's policies, the President doesn't really matter. Until there is a wholesale dumping of senators and congressmen/women, expect things to go on with business as usual.
Unless Trump is elected, in which case this is going to look like the Garden of Eden compared to the post-apocalyptic doomscape America will become with that egomaniacal nutbag in charge. He was endorsed by the grand wizard of the KKK who said, "A lot of what he believes in, we believe in." The conversation over who I'm voting for begins and ends with that statement. As a general rule, I side against the Klan at all times. Kasich was the person I wanted to see in the White House, but he's way too reasonable and intelligent for the job. I'm not exactly excited about Hillary or Bernie Sanders, who would bring a different kind of hellscape to America, but I'd take either in a heartbeat over Trump, who should be a punchline not a presidential candidate.