IN EXCHANGE FOR supporting the eminently reasonable bill to lower the state's DUI level to 0.08 percent, state senators insisted on adding a provision asking the attorney general to go to court and challenge a federal law that threatened to withhold highway funds from states that didn't adopt the lower standard.

Now that the new DUI law is in effect, we are delighted to learn that Attorney General Henry McMaster has declined to squander taxpayer funds on what should be and, in nearly all certainty is, a lost cause.

The argument, penned by Sen. Glenn McConnell, was that the 10th Amendment (which reserves to the states all powers not assigned the federal government) bars the Congress "withholding funds to which a state is otherwise entitled because of a state's failure to enact a state law consistent with some federal goal or policy."

This argument ignores the fact that the Constitution gives the Congress sole authority to determine which federal funds a state is "otherwise entitled" to receive. But that's not the only problem with this quixotic quest.

We've been down this road before, and on an issue that actually had a tint of credibility. In 1999, then-Attorney General Charlie Condon argued before the U.S. Supreme Court that the Congress had violated the 10th Amendment when it told states they could not release information contained in their driver's license files. The court disagreed -- unanimously.

If we couldn't win an argument that the 10th Amendment allows states to decide how to treat state documents, then it is pure folly to believe that we could win an argument that the 10th Amendment somehow limits how the Congress can spend federal tax money.

But even if we could win such an argument, we shouldn't try. Our legislators, of all people, should understand that it is not only acceptable but necessary for a government to attach strings when it gives tax money to other bodies, be they agencies or private entities or other governments. After all, the body that levies taxes is the one responsible to the public for the proper use of that money. In the case of federal highway taxes, that's the Congress, not the S.C. Legislature.

Even if you think the Congress should spread tax money around without conditions, there is something to be said for picking your battles: Debate the merits all you want, but don't march into court every time someone does something you disagree with on principle; you should also disagree with the substance. And, the views of Sen. McConnell and a few other libertarians notwithstanding, there is no legitimate reason to disagree with the substance of the federal law in question. Driving is a privilege, not a right. And federal laboratory research has shown that the ability to brake, steer, change lanes and use good judgment drops by 60 percent to 70 percent when drivers reach a blood-alcohol level of 0.08 percent. Studies of actual highway results in states that have adopted 0.08 laws have consistently shown reductions in alcohol-death rates.

We, too, would have preferred that the federal government not force South Carolina to lower its definition of drunkenness. Unlike the libertarians, that's because we believe the General Assembly should have taken that action on its own. Having finally been dragged kicking and screaming into protecting innocent lives on our highways, the last thing we need to do is make a laughingstock of ourselves -- and squander our precious, dwindling resources -- by launching another ill-conceived fight against the federal government.