The state’s largest coalition of labor unions voted on Saturday to sit out Colorado’s U.S. Senate race rather than endorse U.S. Sen. Michael Bennet because of the Democrat’s position on a controversial international trade agreement.

“The Trans-Pacific Partnership weighed heavily on our affiliates’ decision to remain neutral in the U.S. Senate race,” said Sam Gilchrist, executive director of the Colorado AFL-CIO, in a statement. “We deeply respect Senator Bennet and all he has done for Colorado’s working families. However, the affiliates present at our convention could not reach the two-thirds majority needed to endorse.”

Bennet hasn’t taken a position on the sprawling, 12-nation trade agreement, which awaits ratification by Congress, but the AFL-CIO vehemently opposes the agreement in its current form, arguing that it will cost jobs and encourage out-sourcing by U.S. firms.

In addition, Bennet voted a year ago to give the president “fast-track” authority to negotiate the agreement, an approach that has drawn the ire of unions who charge it guaranteed labor wasn’t involved in the talks.

“Michael’s proud to be supported by a majority of union members across Colorado, and in the Senate he’ll continue fighting for middle-class families and working to get things done for Colorado,” campaign spokesman Andrew Zucker told The Colorado Statesman.

Bennet has won the support of a dozen unions -some are members of the state AFL-CIO – including the International Association of Firefighters, the National Education Association and the Sheet Metal Workers.

The Colorado AFL-CIO counts 170 union affiliates representing 130,000 workers statewide.

“Our decision is to remain neutral,” said Gilchrist in an interview. “Our affiliates and delegates felt very strongly about the TPP. Currently, given the senator’s position on it and his vote for the TPA” – the fast-track authorization, known as Trade Promotion Authority – “they did not feel so inclined to endorse him.”

The Colorado AFL-CIO’s Committee on Political Education – COPE – held its biennial meeting Saturday to vote on candidate endorsements for the upcoming elections. The committee is scheduled to meet again after the June 28 primary to vote on additional endorsements – when the organization hadn’t endorsed in a primary or to reconsider endorsing in a race if a favored candidate loses a primary.

Gilchrist said it was unlikely that COPE will vote again on a Bennet endorsement.

“He’s been a very active senator with us in many ways. If he was to come out against the TPP, we would potentially reconsider our position,” Gilchrist said, adding, “I can’t speak for our executive board, but the larger delegate body has spoken. Barring an entire new convention happening, there doesn’t seem to be much of a chance we’ll change our endorsement.”

The labor organization invited Republican U.S. Senate candidates to take part in the multi-step endorsement process – involving a questionnaire and interviews – but none did, Gilchrist said. Green Party candidate Arn Menconi also sought the endorsement.

Bennet won the Colorado AFL-CIO’s backing in 2010, although the organization declined to make an endorsement in the Democratic primary that year, when former House Speaker Andrew Romanoff was challenging Bennet for the nomination.

Two years ago, according to the campaign finance watchdog OpenSecrets.org site, the AFL-CIO Workers’ Voices SuperPAC spent $383,817 supporting Democratic U.S. Sen. Mark Udall and opposing his Republican challenger, U.S. Rep. Cory Gardner, who went on to win the election.

This year, the Colorado AFL-CIO endorsed U.S. Reps. Diana DeGette, Jared Polis and Ed Perlmutter, all Democrats, and voted to back three Democrats congressional candidates who are challenging Republican incumbents: former state Sen. Gail Schwartz in the 3rd Congressional District, Bob Seay in the 4th Congressional District and state Sen. Morgan Carroll in the 6th Congressional District.

While DeGette and Perlmutter last year voted against granting the administration fast-track negotiating authority on the trade agreement, Polis voted with Republicans Mike Coffman, Doug Lamborn and Scott Tipton in favor of the Trade Promotion Authority bill, which passed the House 218-208.

– ernest@coloradostatesman.com