Here is the specific problem: Insurance companies worry that young people, especially young men, already think they are invincible, and they are bewildered about the health-care reform in general and exchanges in particular. They may tune out, forego purchasing health insurance and opt to pay a penalty instead when their taxes come due.

The consequence would be a disproportionate number of older and sicker people purchasing insurance, which will raise insurance premiums and, in turn, discourage more people from enrolling. This reluctance to enroll would damage a key aspect of reform.

Insurance companies are spooked by this possibility, so they are already raising premiums to protect themselves from potential losses. Yet this step can help create the very problem that they are trying to avoid. If premiums are high—or even just perceived to be high—young people will be more likely to avoid buying insurance, which could start the negative, downward spiral of exchanges full of the sick and elderly with not enough healthy people paying premiums.

Fortunately, there are solutions. First, young people believe in President Obama.