WASHINGTON — Amid talk of spectrum policy and 5G wireless networks, Senate Republicans piled on Federal Communications Commission Chairman Tom Wheeler Wednesday over the FCC’s decision to protect net neutrality.

A report published this week by Sen. Ron Johnson, R-Wis., maintained that the FCC’s decision to regulate broadband Internet service as a public utility was unduly influenced by the Obama administration. The FCC is an independent regulatory agency.

“I hope the commission — rather than resorting to a defensive posture — will look for ways to demonstrate the kind of transparency expected of our independent agencies,” said Senohn Thune, R-S.D., chairman of the Commerce, Science and Transportation Committee.

Net neutrality is the principle that Internet providers should not be able to give favorable service to particular websites and services. Activists and companies like Google and Amazon say that treating Internet infrastructure as anything other than “dumb pipes” would harm freedom of expression and hurt online companies.

Republicans have generally sided with Internet service providers such as Comcast and AT&T against net neutrality, arguing that an unregulated network would hurt job growth and prevent investment in broadband infrastructure.

“The FCC has been known to set aside the intent of Congress, deals struck at the time, reams of its own precedent, and sometimes even the English language itself to “reinterpret” a statute, all in a single-minded pursuit of a particular outcome,” said Republican FCC commissioner Michael O’Rielly.

In a heated exchange Sen. Johnson said that “the FCC turned on a dime” after President Barack Obama issued a statement saying his administration supported net neutrality. Johnson asserted the administration and FCC held off the record meetings.

Johnson’s report was the result of a year-long investigation by the staff of the Senate Committee on Homeland Security and Government Affairs.

“This is very troubling,” he added. “Those discussions were pretty significant.”

The decision to protect net neutrality was hailed as a victory by Internet advocates. A well-shared video by comedian John Oliver in 2014, along with work of countless activists, is credited with bringing the issue to popular attention, flooding the FCC’s website with so many comments it crashed. A 2014 poll found that most Americans — both Republicans and Democrats — don’t support allowing providers to create “Internet fast lanes.”

FCC commissioners from opposite sides of the political aisle clashed over how the 2014 Open Internet Order has affected the Internet market.

“Broadband is not being reasonably deployed in a timely way because the FCC’s policies have failed,” said Republican Commissioner Ajit Pai. “With all due respect to my colleague,” responded Wheeler, a Democrat, “what he has just portrayed as facts, are not. Investments are up. Fiber is up 13 percent over last year.”

The argument is far from over. Just last week two presidential hopefuls, Sens. Ted Cruz and Marco Rubio, endorsed legislation that would “nullify the FCC’s net neutrality rule.”

During the hearing, the senators peppered the commissioners with questions covering all aspects of the FCC’s role, including bringing broadband access to rural communities, regulating wireless spectrum and preventing phone scams.

“The do-not-call list, it doesn’t work,” said Sen. Bill Nelson, R-Fla. “It’s gotten so bad I don’t want a land line.”

Last week Nelson introduced the Spoofing Prevention Act of 2016 which seeks to limit fraudulent caller ID information.