And as such this represents a misconception on Senator Bennet's part.
Wireless broadband in rural areas isn't limited by spectrum, it is limited by infastructure. Cell/broadband frequencies are relatively unused in rural areas. All companies like At&t, Verizon, and Cricket need to do to extend wireless broadband to rural areas is build more towers. They don't need more spectrum. All internet providers except Hughes Net satellite internet are ultimately wired carriers. Their wireless networks only extend a few miles past the "wire." And, unlike broadcasters, all they need to do to get more reuse out of their spectrum is build more towers. Since there are fewer users in rural areas, there is already plenty of broadband spectrum in rural areas, it's just a matter of getting enough fiber lines and towers to utilize that spectrum.
Plus, in areas like Colorado's Eastern border, and Western slope, much of the TV spectrum is "white space" (unused TV spectrum) that could be licensed to local companies to compete against the "big boys" without adversely effecting broadcasting. The NAB has already endorsed such a plan, and it is already in effect in Canada.
Therefore, to meet Senator Bennet's concerns, all congress needs to do is encourage more competing fiber networks and last mile(s) wireless systems. You don't need more spectrum to do that. Plus, the FCC isn't even looking at spectrum above 3.7 GHz even though wireless ISPs have used unlicenced 5.8 GHz spectrum to provide wireless service for years. Like someone else has pointed out, it doesn't work for handheld devices, but it is affordable broadband, not handheld broadband, that is the stated goal here.