Sen. John Thune (R-S.D.) speaks at the South Dakota Republican Convention in Rapid City in June. (Toby Brusseau/AP)

Republicans charged with overseeing the Federal Communications Commission are lashing out at President Obama's proposal for ensuring net neutrality, the principle that all Web traffic should be treated the same by Internet service providers.

In a letter to the FCC, Rep. Fred Upton and Sen. John Thune take aim at Obama's endorsement of aggressive regulation for broadband providers, adding fuel to a growing political dispute between the GOP and Democrats over the future of the Internet.

Highlighting how previous FCC attempts to develop ISP rules led to legal challenges, Upton — who chairs the House Energy and Commerce Committee — and Thune, who is expected to become the top Republican on the Senate Commerce Committee next year, said this time may be no different.

"You are being asked by some to reclassify broadband under Title II of the Communications Act," the members wrote to FCC Chairman Tom Wheeler. "This isn’t sound policy and would almost certainly mean another trip for the FCC to the Court of Appeals."

The letter comes days after Obama called on Wheeler to reclassify broadband, joining consumer groups and tech companies who want "the strongest possible rules" for keeping the Internet free and open. But while Obama cannot directly influence the FCC, which by law is considered an independent agency, a GOP-held Congress would not be bound in the same way. If the FCC pursues aggressive regulations for net neutrality, it could become a political football on Capitol Hill.

"What's likely in the short run," said one industry lobbyist, who spoke on the condition of anonymity Monday because he wasn't authorized to speak on the record, "is that you'll see yesterday's press releases turned into letters, and letters turned into hearings."

Looks like we're getting a taste of that already.