House Speaker Margaret Anderson Kelliher's union backers could nearly build a house by themselves -- she has endorsements from the electricians, the carpenters, the engineers, the laborers and Friday added support from the building and construction trades and the pipe traders.

The DFL-endorsed candidate, however, lacks the steelworkers (their union endorsed DFL rival Mark Dayton) and the building cleaners (SEIU has decided not to endorse before the primary.)

All told, Kelliher has picked up unions representing more than 250,000 members in her bid to become Minnesota's next governor, including the teachers' union and the nurses union, which is more than anyone else running for governor.

"Margaret has been a good friend of the building trades for years," president of the St. Paul Building and Construction Trades Council Harry Melander said.

In recent years, the building trades have backed an expansion of the Mall of America and a new Vikings stadium, both of which could put their members to work.