Nearly three years later — with a presidential election looming and Florida expected to play a critical role in the outcome — those groups are still waiting. The rules, originally scheduled to take effect in March, now won't be active until next January, and even then could be replaced altogether by state-drafted regulations.

In fact, a growing number of regulations are being delayed at federal agencies or at the White House. The list includes a rule cracking down on junk food at school bake sales, another banning children from dangerous work on farms and one setting federal standards for disposing toxic ash from coal-fired power plants.

Together, the delays suggest caution by the administration at a time when President Barack Obama is increasingly under attack by Republicans and business groups for pushing regulations that they say will kill jobs or needlessly extend federal power.