There is little logical basis for excluding women from the duty to register for the Selective Service now that they may fight on the front lines alongside men. Most senators agree: The Senate passed a defense bill last week that would require women turning 18 on or after Jan. 1, 2018, to register for the draft. The House version of the legislation does not include the measure, a difference that will have to be reconciled in conference.

An apt question as legislators debate is whether the Selective Service makes sense at all in the modern age. An all-volunteer force has worked well in the U.S. since 1973. It’s not clear that mass conscription would make sense for today’s high-tech military even if the nation faced a large-scale threat.

The millions of dollars put into maintaining the system each year might be better spent on a more pressing problem: Almost a quarter of the population is not registered to vote. Because studies show that voting is habit-forming, it is particularly important to bring young people to the polls – but they register at even lower rates. Poor registration systems may deter potential voters, and they cause other problems, too: Estimates say about 24 million voter registrations are invalid or inaccurate.

A national system that automatically registered U.S. citizens at 18 could brighten this picture. Five states employ automatic registration through their motor vehicle agencies, and a bill introduced by U.S. Rep. David Cicilline, D-R.I., would make the practice mandatory. Researchers have identified the Selective Service’s automatic draft registration model as one to increase voter registration numbers. Why not shift resources to voter registration, or – if sign-up strictures must stay – tie the two together? We should want citizens not just in the armed forces but in the voting booth as well.