Sen. Eric Coleman, D-Bloomfield, who finds his re-election imperiled by a three-way Democratic primary, picked up the endorsement Wednesday of AFT-Connecticut, which represents Hartford school teachers and support personnel.

Politicians facing August primaries especially appreciate the endorsement of a union whose members are more likely to have the time for phone banks or a get-out-the-vote effort.

Coleman, whose district includes parts of Hartford, Bloomfield and Windsor, faces a three-primary with Shawn Wooden and Len Walker. Wooden, the president of the Hartford City Council, is the convention-endorsed candidate.

Winning the Democratic primary for the seat is usually tantamount to election in the heavily Democratic 2nd Senate District.

Coleman is one of three Democratic senators from urban districts facing primaries. The others are Andres Ayala of Bridgeport and Anthony J. Musto of Trumbull, whose district includes part of Bridgeport.