The Republicans in Congress are going forward with their vote to repeal the healthcare bill even though they know that it won’t go anywhere; the Senate won’t pass it, and even if they did, the president would veto it. So why bother?
It’s pretty simple, really. They all campaigned on it, saying they would vote to repeal it, so for once they’re keeping a campaign promise. And they have to vote to repeal it all. They can’t offer bills that would change the current law because if they did, they would be fixing the flaws that have become apparent since the bill passed, such as the individual mandate. That would be an admission on the part of the Republicans that there are actually some good things in the bill, and they can’t have that; there’d be nothing left to demagogue and raise money against.