Nobody is impeaching anyone. Nor are they going to pass any “fix” or revamped version of Obamacare.
If the Supremes toss it out this issue will be D-E-A-D until the next time the Dems get super-duper majorities in both houses (which will hopefully be never)
Obama and friends will go around the court’s decision, if not ignore it outright.
If by some wild fluke Romney gets elected president there will probably be Dem super majorities after 2014 and almost certainly after 2016 along with a rerun of the kenyan, either himself or another Soros nominee.