KANSAS CITY, Mo. — Missouri’s Democratic attorney general broke with his party on Monday and urged a federal judge to invalidate the central provision of the new health care law.
The filing of the brief by Attorney General Chris Koster, a onetime Republican state legislator who switched to the Democratic Party in 2007, underscores the act’s political tenuousness in a critical Midwestern swing state.
Mr. Koster’s action followed months of pressure from state Republicans that he join attorneys general from other states who are challenging the constitutionality of the law.
Rather than join the litigation, however, Mr. Koster chose to file a “friend of the court” brief in the United States Court of Appeals for the 11th Circuit, in Atlanta, which is reviewing one of five challenges to the act that have moved into the midlevel appellate courts.
Three lower court judges have upheld the law, while two have ruled that its central provision — the requirement that most Americans obtain health insurance — is unconstitutional.
The 11th Circuit is hearing a case filed in Pensacola, Fla., by Republican governors and attorneys general from 26 states. The federal district judge in that case, Roger Vinson, decreed that the entire health care act should be invalidated, but stayed his ruling until the Supreme Court settled the matter.
In Missouri, a ballot referendum aimed at nullifying the law was approved by nearly three to one last year, and the legislature recently passed resolutions urging Mr. Koster to join the legal challenges. The state’s lieutenant governor, a Republican, filed a lawsuit last year seeking to block the law.
In a letter to the Republican leaders of the legislature announcing his decision to oppose the law, Mr. Koster acknowledged that the legislative resolutions, though nonbinding, were “impactful, as they give voice to the political will of Missourians.”
Although he supports an expansion of health coverage, he wrote, his duty is “to the law, and not to a political outcome.”