The Right to Organize
As an independent contractor, the terms and conditions of the work you perform are set out in a contract between you and the employer. Even though you are not considered an “employee” under federal labor law, you may still join a union. However, you should keep in mind that a unit of independent contractors is not subject to the same privileges and protections as a regular union bargaining unit. For example, an employer is not under the same obligation to bargain with a union regarding contract terms for an independent contractor that it is to bargain over issues affecting its regular employees. Also, an independent contractor who went on strike would not be protected from employer reprisals under the National Labor Relations Act.
www.cwa-union.org/
The main impediment would be possible anti-trust action being taken against any such union.
So continue to bend over and take it without Vaseline, if you insist.