Unions are a relic whose time has come and long gone.
We have labor laws on our side now and if you are a contractor worth his/her salt, you'll have all the documentation
you need to get paid in order and ready to roll in case the Prime or Sub that you work for starts to play with your money.
It's even more likely that any riff raff that might try to beat you out of your dough will think again if they see that your paper work is airtight and that you have the determination and documentation
to bring about a successful claim 
(and any more punitive damages that may come with a judgment). 
If you do spec work and have your paperwork in order and you ALWAYS CYA in all things you do, you’ll never get beat out of money coming to you.
Just IMHO
