King County Council chair Bob Ferguson—a potential Democratic contender for the attorney general's office in 2012—sent a letter this afternoon to current AG Rob McKenna, a Republican, blasting McKenna for joining a 13-state lawsuit against recently passed health-care reform legislation. (McKenna's basic argument is that it oversteps the bounds of the Tenth Amendment to require people to purchase health insurance).

In the letter, which is also signed by King County Executive Dow Constantine, state Sen. Adam Kline (D-37), and state Rep. Jamie Pedersen (D-43), Ferguson expresses "skepticism" about the legal grounds for joining the lawsuit; notes that the suit will take up "precious taxpayer resources" that could be used elsewhere; criticizes McKenna for entering a multistate lawsuit without input from the state legislature or Gov. Chris Gregoire (who opposes McKenna's decision); and calls the decision "contrary to the interests of our state."

Health care reform, Ferguson writes,

increases the health security of our state's residents by providing significant new protections to Americans from the most condemnable conduct of the health insurance industry. ... With so much to do here at home, entangling our state in complex federal litigation on the other side of the country is not in the interest of our citizens. We ask that you reconsider your decision.

Ferguson has not yet said whether he will run for attorney general in 2012; McKenna, meanwhile, is  considering a run for governor.