One by one, the myths of the Affordable Care Act have been revealed. When the curtain on open enrollment falls on March 31, the last remaining big myth of ObamaCare will be fully exposed: The individual mandate has failed.

After a last-ditch effort with President Obama himself encouraging "young invincibles" to sign up before the deadline, the administration is scrambling to boost enrollment. On Tuesday, the White House announced that people who applied for coverage on the federal health-insurance exchange will have...