Part of the problem in challenging the constitutionality of health care reform - specifically, the individual mandates - is that the Supreme Court has shown over the years that they are very reluctant to pick a fight with Congress.

This Jess Bravin piece in the Wall Street Journal highlights some of the roadblocks:

Constitutional-law scholars say that if the health-care overhaul becomes law, it could give courts an opportunity to test the limits of congressional authority in areas that haven't been examined since the New Deal era. However, courts usually defer to lawmakers, and Democrats could smooth the way further by using language in the final version that clearly asserts Congress's power under the Constitution to levy taxes -- which the House bill already does.

Sen. John Ensign, a Nevada Republican, tried last month to hold up the bill on grounds that Congress lacked authority to enact it. The move failed, with 60 Senate Democrats and independents outvoting 39 Republicans.

Last week, the Texas attorney general, Republican Greg Abbott, wrote that a federal mandate to carry health insurance "threatens individual liberty." Florida Attorney General Bill McCollum, a Republican running for governor, held a press conference in December to make the same point.

Democrats dismiss the Republican arguments as a last-ditch effort by the minority party to block the majority's will. They say the plan is grounded in basic powers the Constitution grants Congress: to regulate interstate commerce, collect taxes and "provide for the general Welfare."

Since the New Deal era, the Supreme Court has broadly interpreted congressional authority under the Commerce Clause. Congress has successfully invoked that power to limit the amount of wheat farmers can grow, ban racial discrimination at restaurants and prosecute medical patients for raising marijuana to alleviate their symptoms.

Why would the Supremes be hesitant about challenging the judgment of Congress when it comes to the legality of the mandate? Because at bottom, this is about the right to tax. And the Supreme Court has almost always accepted the idea that this right is pretty much what Congress says it should be.

Still, as the Journal article points out, health care reform is "novel" in its approach to taxes and interstate commerce regulation. Whether that will be enough to convince the court that the Constitution actually means what it says about freedom is another story.