Julian Zelizer: For Health Reform, Now the Tricky Part

(CNN) -- White House officials rightly breathed a sigh of relief when the Supreme Court upheld the Affordable Care Act. President Obama and his supporters are optimistic that his re-election prospects are stronger and his lasting impact on domestic policy will be much greater.

But the battle has only begun. Even after legislation is enacted, as the political scientist Eric Patashnik says in his book "Reforms at Risk," its survival is not assured. The key to success is whether a program lasts over time and builds strong political support to protect it from future attacks. As Patashnik and political scientist Jeffrey Jenkins wrote in a recent blog post, before the Supreme Court ruled: "The partisan and ideological struggle over health-care reform is likely to continue under any scenario."

Congressional Republicans will likely continue attacking the program's funding. House Speaker John Boehner has vowed to push for its repeal.

Mitt Romney has said he will do the same if he is elected president....