President Obama today ordered federal government agencies to sweep their regulatory histories going back ten years for any regulation that would preempt or block stronger state laws and remove them, reversing a long-running trend towards “preemption” of laws that protect consumers at the state level.

The memorandum, released today by the White House and published in the Federal Register, affirmed that “Throughout our history, State and local governments have frequently protected health, safety, and the environment more aggressively than has the national Government.”

“In recent years…executive departments and agencies have sometimes announced that their regulations preempt State law, including State common law, without explicit preemption by the Congress or an otherwise sufficient basis under applicable legal principles,” the statement added.

Under the new directive, heads of federal agencies would not be able to issue regulations that conflicted with state law unless the regulation specifically included language describing the preemption, or that did not cohere with existing federal orders governing preemption.

The Constitutional Accountability Center (CAC) hailed the decision as a rebuke of the Bush administration’s frequent usage of preemption, saying that “President Obama reaffirmed the critical role that state and local governments play in our constitutional system.”

In recent years, numerous industries have argued that federal laws should preempt state laws on a variety of topics, from roof strength standards for cars, to predatory lending laws, to cell phone contracts. The common business argument has been that a single, simple federal standard is easier for businesses to navigate than a patchwork of 50 different state laws.

Critics charge that the real reason businesses favor federal preemption is that it’s easier to lobby a few lawmakers on Capitol Hill to pass weak federal laws that block stronger state laws, and that national law should be a floor, not a ceiling, for state laws.

Ian Millhiser, an attorney with the National Senior Citizens Law Center, said that “President Obama’s policy memorandum shows that he understands that the federal government cannot be an obstacle to states who want to protect their citizens in a manner that goes above and beyond bare federal standards.”