Beyond deepening gridlock, President Obama’s expansive doctrine of executive discretion may prove self-defeating in another way. For the next Republican president, nonenforcement of key provisions of the ACA, based squarely on precedents set by the law’s champion, may be an enticing alternative to legislative repeal.

Take the individual mandate. Secretary Sebelius justified waiving that provision on the inventive theory that the ACA’s intended effect—the elimination of noncompliant health plans—qualifies as a “hardship” under the ACA. This is the legal equivalent of a cat chasing its tail. Elimination of what the law’s backers deride as “garbage plans” was once thought to be a blessing of the ACA, not a hardship. But Ms. Sebelius announced that cancellation-letter recipients need only request an exemption and certify that they “consider other available policies unaffordable.”

A modest extension of this rationale would make the individual mandate a dead letter. With premiums on the rise, the next Republican administration might plausibly assert that available policies continue to be unaffordable for millions of Americans due to new costs imposed by the ACA’s minimum-coverage requirements—a “hardship” under Ms. Sebelius’s logic. If that rationale applies to those whose plans were canceled, it would seem to apply equally to anyone who can no longer afford insurance due to the effects of the law. On that basis, the next administration could, like Ms. Sebelius, exempt any American who “considers . . . available policies unaffordable.”