Unions and Democrats have had a rocky enough relationship for years now, mostly because union membership has dwindled and Democrats haven’t done “enough” for unions. Losing takes its toll on coalitions after a while.
Unions give money and time almost exclusively to Democratic candidates and causes, and in return they expect a lot of pull within the party and their issues to have priority. The Party is trapped right now, because many Washingtonians see unions as job-stoppers, not job creators. So Dems can lose independents and this election by hugging their supporters, lose long-time support from unions, or try to toe the line by telling unions they don’t have the votes in a state where Democrats have ruled exclusively for 20+ years, while telling everyone else they are pro-business/pro-jobs (who isn’t pro-jobs, BTW?)
Which is what they’re doing now. Expect lots of this doubletalk between now and the 2012 election.