Dr. Beth Haynes pointed me towards this nice video, with the message that the new Congress has a mandate to repeal ObamaCare:
Of course, immediate repeal is extremely unlikely in the face of Obama's presidential veto.
But the GOP can "defund" it. And interestingly enough, this pro-ObamaCare article in the New England Journal of Medicine tells how it can be done:
"The Midterm Elections - High Stakes for Health Policy" (PDF file)
(Go to the 2nd page of the article in the paragraph that begins, "A more serious possibility is that ACA opponents could deliver on another pledge: to cut off funding for implementation. Here is how such a process could work...")