An underwhelming five million Americans have signed up for coverage in the new health insurance exchanges so far. That’s far short of the Obama administration’s goal of seven million enrollments by the March 31 deadline. It’s human nature to wait until the last possible minute, so there’s a good chance that the number will rise significantly in the remaining 10 days. In fact, the Congressional Budget Office projects another one million enrollments before the deadline.

But six million is still one million short of the goal. That gap is disappointing, and Republicans are almost certain to pounce on it as another failure of the Affordable Care Act.

When the exchanges first opened on October 1, 2013, the federal exchange site (www.healthcare.gov) was beseeched with glitches that made it nearly impossible for anyone to sign up. To make matters worse, these hassles disproportionately dissuaded younger, healthier people from enrolling. After all, younger adults tend to be more technically savvy as a group than older adults and have less patience for more traditional forms of enrollment like paper or telephone.