PORTLAND — The Maine State Troopers Association, which made no endorsement for governor in 2010, is endorsing Democrat Mike Michaud (MEE’-shoh) in the three-way race.

Union President Aaron Turcotte said Monday that Michaud was selected over incumbent Republican Gov. Paul LePage and independent Eliot Cutler because he possesses the core principles of troopers — “integrity, fairness, compassion and excellence.”

LePage’s campaign responded that Michaud, if elected, would be beholden to “big labor union bosses.”

The union has endorsed both Democrats and Republicans over the years, including Republican U.S. Sen. Susan Collins, former Democratic Gov. John Baldacci and Republican Peter Cianchette, who ran for governor in 2002.

Turcotte said the union withheld its endorsement in the 2010 race featuring Cutler, LePage and Democrat Libby Mitchell.