When the House of Representatives voted to prohibit lawsuits that blame gun manufacturers for crimes committed with their products, only four Republicans opposed the bill. Three of them were reliable supporters of gun control, but the fourth, Ron Paul of Texas, is a self-described "firm believer in the Second Amendment" who has received high ratings from the National Rifle Association and Gun Owners of America.

 What led Paul to join his anti-gun colleagues in voting against the Protection of Lawful Commerce in Arms Act? The same thing that led to accolades from groups that defend the right to keep and bear arms: his respect for the Constitution.

 As Paul explained in a 2003 speech, he is unambiguously opposed to lawsuits that demand compensation from the firearms industry for the damage caused by gun crimes. But he concluded that federal preemption of such suits cannot be reconciled with the Constitution's limits on congressional power, which leave the writing of tort law to the states.

 Paul seems to be the only member of Congress who took this position on the bill, which President Bush signed into law on Wednesday, Oct. 26. In fact, it's so rare for legislators to draw a distinction between their personal policy preferences and their constitutional responsibilities that Paul's stand must seem quaint, if not downright puzzling, to most Americans.

 The strongest argument in favor of federal limits on gun lawsuits was that legal costs and the threat of a ruinous judgment might push gun makers into a settlement that included nationwide restrictions on sales, impinging on the authority of state legislatures and the right to armed self-defense. But this danger never materialized.

 Of more than 30 government-backed lawsuits filed since 1998, all but a few were dismissed before Congress acted, at which point 33 state legislatures had passed similar laws. In short, there was no constitutional emergency to justify congressional meddling in state tort law -- a fact reflected in recent statements from the leading supporters of federal preemption.

 Press releases from the NRA and the National Shooting Sports Foundation, the main industry group, said the new law will foil frivolous lawsuits, protect law-abiding businesses and save American jobs. There was no mention of the Constitution or the Second Amendment.

 This casual attitude regarding the constitutional legitimacy of federal tort reform is even clearer in the case of the Personal Responsibility in Food Consumption Act, which the House approved by a wide margin the day before it voted to restrict gun lawsuits. The "cheeseburger bill" would bar lawsuits in which portly plaintiffs seek to blame food sellers such as McDonald's for making them fat, unless the defendant can be shown to have violated an express warranty or a state or federal law.

 As with the gun lawsuits, state legislatures (about 20 at last count) already have acted to stop this sort of litigation, which in any case represents a less serious threat to the companies it targets. Only one such lawsuit is still pending (based on statutory claims that would not be barred by the proposed federal law), and the food industry has much deeper pockets than gun manufacturers do. Even if purveyors of fast food and other calorie-dense comestibles were in imminent peril, advocates of congressional intervention would have a hard time locating a constitutional right to buy cheeseburgers.

 Instead the bill notes that "the activities of manufacturers and sellers of foods and beverages substantially affect interstate and foreign commerce." This justification relies on a reading of the Commerce Clause so broad that it erases the distinction between state and federal powers.

 How can anyone who claims to respect the Constitution sign onto such self-serving nonsense? Bob Barr, the former Republican congressman from Georgia, says opposing federal preemption of gun lawsuits on constitutional grounds amounts to "unilateral disarmament." Yet failing to do so amounts to dismantling our defenses against those who believe Congress can and should bend the Constitution to their will.