In the short run, yesterday's Supreme Court decision upholding the individual mandate in Obamacare was a win for the President. It means that he has something to show for his first term besides a sluggish economy and the head of bin Laden (which cannot be shown). That short run may have already expired. Obamacare is still unpopular and the ruling on Medicare means that it will be more expensive. Polls taken before the Court's ruling showed that 75% of the country was hoping that it would be overturned. Conservatives just plain don't like it. Liberals really wanted single-payer and are afraid that they will never get it as long as Obamacare stands.
This adds an urgency to Romney's campaign. For the last couple of months it was assumed that Obamacare would be struck down leaving the economy as the main issue. Realists know that Romney will be limited in what he can do to stimulate America in a world economy. Conventional wisdom says that the economy will not get any worse if we keep Obama. That makes it harder for a challenger.
Now Romney has a second issue and a clearer choice. Obamacare will not be repealed while Obama is in the White House, If you want the law overturned then Obama has to be voted out.
A lot of people already figured this out. Romney's campaign received over $4 million yesterday. Much of this came from small donors who have previously not given Romney much money.
President Obama has already suggested that we should accept the Court's decision and move on. Romney's response is that the Court ruled that the law is constitutional, not that it is a good law.
Another problem for Obama is that the Court ruled that the individual mandate is a tax. This will hit the young and poor the hardest, violating Obama's pledge that he would not raise taxes on anyone making less than $200,000/year.
So, while Obama might be pleased that the legislation that was to be his legacy survived, it remains unpopular and will serve as a rallying point against Obama's reelection.