Whether public employee unions would make good on a threat to support challengers to former Democratic allies was an open question—until now.

The Portland Association of Teachers has decided to endorse the challenger to three-term incumbent Rep. Rob Nosse (D-Portland) after his vote to cut retirement benefits of public employees.

Paige Kreisman, a disabled veteran who is the first candidate to win the endorsement of Portland's Democratic Socialists of America, won the teachers endorsement in part because of Nosse's decision to vote for Senate Bill 1049 last year.

PAT made a case for her values as well.

"Paige Kreisman deeply believes in fully funding public schools, strengthening workers rights, and providing needed human services to all Oregonians," the PAT PAC's endorsement reads.

"The passage of SB 1049 last summer—which reallocates a portion of public employee compensation away from workers' retirement savings, to use it to pay down the state's debt—was deeply troubling to teachers and all public employees.

"A vote for this bill represents a lawmaker's willingness to forgo agreements made in trust, and to force public workers to pay for the state's programs."

PAT's endorsement striking in part, because Nosse, a former employee of the Oregon Nurses Association and SEIU, is one of the most progressive and labor-friendly members of the House.

Here's how PAT explained its choice to members:

This primary season, the PAT PAC is not endorsing any candidate who voted for SB1049. We are hopeful that moving forward, our Oregon Legislature will be bold champions for workers, public education, and the revenue reform to allow our state to meet the needs of all our state's children, families, and community members.