The Corrupt Practices Act of 1912 was a demonstration of the shift from corporate control of the state house to one where corporations were viewed very warily. It was recognized that a corporation is more likely to act in its own interest than that of the state or its citizens.
In the decades since then, this has found its way into many pieces of law and the political consciousness of Montana appears to be one that still views corporations through a wary eye. It is recognized that it is the responsibility of the state is to protect its citizens from corporations. Going by http://www.nclc.org/images/pdf/udap/report_50_states.pdf , Montana has fairly strong consumer protection.
So, let me rephrase my original statement... Montana is a state that appears to value protecting its citizens more than corporations as demonstrated by its challenge (the only state that did so) to Citizens United. That Montana is attempting to implement net neutrality should come as no surprise when one looks at the history of the state and its relationship with corporations.