One large fact that I see many people overlooking in this discussion is the fundamental state of our internet infrastructure today, and the reason why there is relatively little competition within geographical areas to provide broadband access. The vast majority of modern broadband is transmitted by wire, either through adaptation of existing lines (DSL and power modulation), or through digital transmission cable.
The companies which own these lines are the companies which offer internet services. It is often not financially feasible for businesses to run new lines into areas which are already offered basic features, unless they can offer some vastly superior and more desired service. Any form of anti-trust would force providers to waste capital on new construction, which would indeed be detrimental to our economy. This exact problem is seen in civic engineering fields, including power distribution and waste management, and is solved by legislation.
This is where market competition theories ultimately fall flat to protect the "open internet". ISPs, by their municipal nature, cannot effectively compete. The cost of running redundant lines is economically prohibitive. This may change if new technologies are developed, but that is not likely, based on projections of the continued convergence to wired, dedicated digital transmission lines. Regardless, any such technological change or innovation in this respect could be provided for in legislation.
The above statements being considered, I believe every sincere United States citizen can agree that the access to methods of free communication is essential, and hence no citizen should be denied access to what is recognized as the open internet, just as they are not denied access to move and talk freely. This is not to say that controlled or restricted access should be denied. In fact, there are many practical advantages to strictly controlled and closed networks, especially including our military and its duty of national defense. But if current national providers do want to offer these closed forms, they must offer them in conjunction with what we experience as the free, open internet. This is the legislation we need.