Democrats from President Obama on down have been touting Obamacare's sign-up numbers. Even after the system's disastrous rollout, they like to point out, roughly three million people have signed up for private insurance, while 6.3 million have signed up for Medicaid. "Already, because of the Affordable Care Act, more than nine million Americans have signed up for private health insurance or Medicaid coverage," Obama said in the State of the Union speech. "Nine million." The number is a little larger now, since the figures are a few weeks old. But there is strong new evidence to suggest the administration's claims...