Periodically there are attempts to unionize engineers in Silly Valley. I've never seen one come anywhere close to success. Most of the engineers I've worked with have seen unions as rent-seeking organizations that simply want to line their own pockets.

(There are similar periodic attempts at licensing software engineers at the state level in CA. These generally don't go well either, and appear to be the same kind of rent-seeking behavior as unions, judging from the howling nonsense proposed as core competencies to test against, e.g., lots of EE knowledge, and stuff involving obsolete technology and software development models that don't work).