Actually, unions can be open shop or closed shop. If they are closed shop, you must join. That sucks. I had several jobs like that. One was a lousy part time retail job! They union dues were more than what I was earning! They kept threatening me saying if I didn't start paying dues, they would deduct them from my check, so I quit! I got issues with the unions. I had a thread on them awhile back. My beef is that until you pass probation (90 days), they really can't help you anyway. And, most union reps are chicken, and don't want to make the princpal mad, so they don't do their jobs. Finally, IMO..once you get the union involved, your name is mud, and you gotta walk the straight and narrow for 180 days from then on. If you so much as sneeze and someone says 'bless you' and you don't say thank you, princpal will right you up for being insubordinate and disrespectful to others! I know they help keep workplace safe, and manage good salaries...but I never felt they were worth all that money they took from me!