The Affordable Care Act is President Barack Obama's signature achievement. This may be his most memorable promise: "If you like your health care plan, you'll be able to keep your health care plan, period. No one will take it away, no matter what."

Those 26 words are from a June 15, 2009 speech to the American Medical Association. Obama offered the same assurance several more times, both before and after Congress approved the health care reform law in 2010.

Ultimately, Obama can't keep his ill-advised promise and still achieve health care reform.

On Thursday, battered by reports of canceled policies and sagging support for the law, the president delivered on his promise — but just for one year.

Obama announced new rules allowing people to keep bare-bones policies that don't comply with the Affordable Care Act. The extension covers only existing policies; insurers can't sell new policies that don't include the law's minimum benefits.

"This fix won't solve every problem for every person, but it's going to help a lot of people," he said.

This is a strategic retreat, not the unconditional surrender demanded by congressional Republicans. It buys time for the administration to resolve technical and political issues exposed during the rollout of Obamacare, as the health insurance program is widely known.

Despite technical problems with the federal website, uninsured Americans are seeking coverage. More than 106,000 people have purchased health plans since enrollment started on Oct. 1. Nearly 1.1 million more have been approved but have yet to select a plan, and 396,000 have been qualified for Medicaid or the children's insurance program.

Obama's "keep your health plan" guarantee falls squarely into the category of self-inflicted political wounds. He couldn't keep that promise, with or without the health care law.

Insurers continually change the scope of coverage, copayments, premiums, referral rules and even eligible providers. The sole alternative for policyholders is finding other coverage — if they can.

If your insurance is an on-the-job benefit, your employer makes that choice for you. In the individual market, annual premium increases of 30 percent or more have been common in recent years, with many people forced to do without or buy expensive policies with unreasonably low coverage limits, dubbed "junk health insurance" by Consumer Reports.

The Affordable Care Act relies on near universal coverage to fund health care. The law requires everyone to obtain insurance, and it requires insurers to take all customers.

Much as state auto insurance laws set minimum levels for liability coverage, Obamacare sets a threshold for health insurance benefits. The law was written to weed out junk policies, and they've been the primary source of uproar over cancellations and premiums.

After the botched rollout of the website, and facing nervous Democrats in Congress, Obama lacks the political capital to enforce the minimum coverage rules, especially given his own ill-chosen words. But giving in would threaten a more fundamental promise: affordable, comprehensive health insurance for all Americans.