The vigorously argued case out this morning from Bernstein Research’s Paul de Sa goes to the heart of the debate over the FCC’s planned net neutrality rules — expected to be adopted on Thursday. Will the proposal built on reclassifying the Internet as a regulated communications service lead the FCC to control broadband rates, potentially chilling investment? FCC Chairman Tom Wheeler says his plan will specifically reject that power. But cable and telco broadband providers say that officials will inexorably end up going there. This week MoffettNathanson Research’s Craig Moffett said he didn’t buy Wheeler’s assurance, one reason why he stopped urging investors to buy stocks in Comcast, Time Warner Cable, and Charter.

But de Sa urges buyers to ignore what he calls “the increasingly alarmist statements made by broadband providers, their paid proxies, and other skeptics” who oppose reclassifying broadband under what are known as Title II rules. Current regulations that “carriers now love and urge the FCC to use unsparingly” already give the FCC “pretty broad” authority to regulate rates.

They don’t use that power, he says, because they don’t want to — and don’t have the means to do so. The FCC “has neither vast retail-rate-setting resources…nor the cost studies and models that would be required to establish a methodology and set rates.” If Wheeler, or a future chairman, wanted to change that, he or she would find it “a complicated, multi-year process, subject to lengthy Court review.”

And if he’s wrong, and the FCC did get into the broadband rate setting business? It might not be so bad, based on the experience of small rural telcos that the FCC does regulate as public utilities. They are “doing just fine with their guaranteed 11.25% return on capital under the supposedly profit crushing” rules that limit them to charge “just and reasonable” prices.