I think that entrenched businesses don't have much of an incentive to be defenders of free enterprise, insofar as their mission changes from bringing a product to market to maintaining the status quo once they reach a stable point in their maturity. It behooves a company, supposing they have the resources, to encourage legislation that not only strengthens their own position, but weakens that of new players. Unions could certainly be accused of the same thing. In fact, I think that is the primary reason that there has been a public backlash against unions in the past few decades. Most people don't have first hand experience as entrepreneurs, but most people do have experience looking for a job. A union can be a giant barrier to entry, and an even bigger barrier to success for certain types of workers (for example, a guy wants to do his best, but is barred by work rules from doing anything but his very specific duty, or a woman wants to move up in the company but is passed over because someone of lesser caliber happens to have more seniority).