Sen. Cory Booker is leaping into the political fight over whether to let cities build and operate their own Internet service.

On Thursday, the New Jersey Democrat will introduce a bill that would help local towns set up public alternatives to big Internet providers such as Comcast or Verizon. It would amend the nation's signature telecom law — the Communications Act — to make it illegal for states to prohibit municipal broadband through new regulations or state legislation.

Booker said more cities should aspire to be like Chattanooga, Tenn., which offers public broadband plans at speeds of 1 gigabit per second for $70 a month. But many are held back, he said, by "industry that wants to maintain monopolies in many ways."

Allowing cities to invest in high-speed fiber optic networks would stimulate economic development and access to education, Booker added.

"That's what created the Internet in the first place, is government-led investment in certain areas," he said.

Booker's bill, the Community Broadband Act, seeks to counter other attempts by the GOP to strip away federal regulators' authority to promote city-run broadband. Republicans and other critics of municipal broadband say such projects are often subject to cost overruns at the public's expense.

Defenders of municipal broadband argue that it can be an effective solution where competition among Internet providers is lacking. Tom Wheeler, chairman of the Federal Communications Commission, said last year that only a quarter of the country has a choice in buying high-speed broadband — the rest live under an effective monopoly or duopoly.

Roughly 20 state laws are on the books making it more difficult for cities to start competitors to large, established Internet service providers. In a speech last week, President Obama asked the FCC to intervene against these state laws. But in doing so, Obama set the stage for a big fight over the issue. Opponents of municipal broadband argue the FCC, a federal agency, is not allowed to step in between states and the cities they govern.

Booker's bill would address that tension by telling the states directly that they cannot block cities from building their own Internet networks.

"While government may seem scary to some people, I wouldn't be sitting here today if it weren't for the government protecting my rights," Booker said in a Senate Commerce Committee hearing Wednesday.