Objecting to what they term an "Obamacare power grab," a group of small business owners and individuals in six states filed suit today against the Internal Revenue Service over a rule that expands health insurance subsidies.

The plaintiffs say the IRS regulations "actually serve to financially injure and restrict [their] economic choices" and are arbitrary and capricious, according to the complaint filed in U.S. District Court for the District of Columbia by Jones Day partner Michael Carvin, who co-argued the U.S. Supreme Court cases challenging the Affordable Care Act in March 2012.