Where I used to work (in New Mexico) did come under California's union laws; at least one union did try to organize (they may still be doing so) the scientists. They said that they would represent us (for about $1200/yr) except in matters of salary, health care, benefits, retirement, management problems, or work conditions.
$1200 a year is steep! IAM isn't even that high. One of the largest professional aerospace unions in WA charges around $30 a month for full representation. It is also tax deductible. They even negotiated $6 million a year for in-house training opportunities.
I don't know what the teachers unions charge.