The Massachusetts Institute of Technology economist who made national headlines last year for talking about "the stupidity of the American voter" is a target of a Vermont state audit that suggests the economist may have padded bills for economic modeling work on a proposed Vermont health system.

Auditor of Accounts Douglas Hoffer offers as evidence Jonathan Gruber's bills for 1,000 hours of work in 10 weeks by a research assistant. The attorney general says Hoffer raises "serious questions."

Gruber says Monday he doesn't wish to comment.

Gruber was an adviser to the Obama administration on the federal Affordable Care Act, when he once said that voter stupidity and a "lack of transparency" helped get the legislation passed. He later apologized repeatedly, saying his comments were uninformed "and sometimes downright insulting."