The Republicans always promote self-sufficiency by becoming your own boss. Frequently, those that have become independent contractors do not do well financially. The Independent Contractors that eek out a living on their own would be better with unions and gainful employment. Employment with benefits and good quality healthcare.
Successful earning Independent Contractors can also benefit by creating there own unions or joining an existing union to share costs of business like health care costs or larger supply purchases. Bargaining as a union of independent contractors can ease responsibility and extract more profits. It would provide more time home with the family.
There is no harm in a bill that support unions. It is collective bargaining and that is all it is. Every American needs to consider the strength in being a part of a collective bargaining organization. There is no downside to this.
The best example I can think of right now are truckers unions. There is The International Brotherhood of Teamsters, but also, NAIT, the National Association of Independent Truckers.
Most independent contractors already have associations somewhere to help with operating costs. There is no downside to unionization or a legislative agenda that supports them.