Washington D.C., the nation's capital, has a dubious distinction. It is also the capital of AIDS infections, with the highest rate of AIDS of any major U.S. city.

There's another shameful fact about Washington that may be linked to the first. For nine years, until the law was changed last week, it was the only city barred from using local funds for programs that provide clean syringes to drug users -- an accepted strategy to combat the spread of HIV and AIDS.

Unfortunately, Congress wouldn't accept the public-health benefits of needle-exchange programs that have proved effective elsewhere. With its paternalistic oversight of the city's budget, myopic members of Congress were in a position to indulge their biases. Two conservative Republicans were able to insert language barring needle exchanges, on the theory that providing clean needles to users only contributes to the drug problem.

This folly has proved in practice a prescription for disaster for residents of Washington, D.C., and their families. The African-American population has been particularly hard-hit by the epidemic, with HIV and AIDS spreading fastest among black women.

It would be nice to think that these grim facts were decisive in stripping the law of the odious prohibition against needle exchanges. Instead, the change in the law owes more to a change in the leadership of Congress. Because Democrats were prepared to face reality at the intersection of compassion and common sense, President Bush was sent a budget bill that allowed the district to use its own funds for needle exchange programs. To his credit, Mr. Bush signed the bill.

Washington city officials hailed the ban's defeat as a real life-saver and announced that $1 million would be earmarked for the program in 2008. The Democratic-controlled Congress can't claim a long list of great achievements since taking up the reins of power, but little things can make a big difference. This was one. A blow was struck for good sense in a matter of life and death.