Health Care Reform in the Courts

Health Care Reform has now started to come before the Courts. The main deciding factor in what will determine the outcome of these challenges when it gets to SCOTUS will be, is, is the Constitution a limiting or enabling document.
Does the Constitution limit Federal power to those enumerated and reserved to the Federal Government, or does the Constitution enable the Federal Government to assume others powers not necessarily enumerated or delegated outright.
How the Justices view the Constitution in this matter, will determine whether portion or most of the bill is struck down, or allowed to stand.