WASHINGTON After weighing the decision for months, Louisiana Sen. John Kennedy joined U.S. Senate Democrats in passing a measure Wednesday to restore Obama-era “net neutrality” internet rules aimed at ensuring equal treatment for all web traffic.

Kennedy was one of just three Republicans to back the effort, which faces an uncertain chance in the House of Representatives and opposition from President Donald Trump’s White House. Sens. Susan Collins of Maine and Lisa Murkowski of Alaska were the other two Republicans voting “yes” on the measure, which passed the Senate 52-47.

Sen. Bill Cassidy, R-Louisiana, cast his vote with the vast majority of other Republicans opposing the move, which would undo the Federal Communications Commission’s December decision to repeal the 2015 set of regulations. Cassidy and other opponents argued the net neutrality rules would stifle innovation on the internet.

At issue are rules the Federal Communications Commission repealed in December that prevented providers such as AT&T, Comcast and Verizon from interfering with internet traffic and favoring their own sites and apps. Critics, including the Trump administration, said overregulation was stifling innovation, and they backed the FCC's move, which is still set to take effect next month.

“I don’t support government regulations stifling internet innovation. Obama’s internet overreach did not make the internet what it is today, American innovation did,” said Cassidy. “Congress should end their partisan back and forth and find a solution that gives internet users long term protection without inhibiting innovation online.”

But backers of the effort, who’ve led a months-long campaign to save net neutrality, have argued ditching those rules gives large internet service providers too much leverage to squeeze smaller startups or provide fast track preferential treatment to favored websites, apps and streaming services.

“I don’t think the cable company should be able to choose which websites download quickly, which websites download slowly and which websites don’t download at all unless you pay them more money,” said Kennedy. “I believe in freedom of connection — freedom of connection is part of free speech.”

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Some Republicans described the Democrat-led effort to reinstate net neutrality as “political theater” because the GOP-controlled House is not expected to take up the issue and the Senate's margin could not overcome a presidential veto.

Democrats, however, were undeterred, saying their push would energize young voters who are tech savvy and value unfettered access to the internet.

"This is a defining vote. The most important vote we're going to have in this generation on the internet," said Democratic Sen. Edward Markey of Massachusetts, who sponsored the measure.

Markey said net neutrality has worked for the smallest voices and the largest, but he said internet service providers are trying to change the rules to benefit their interests.

Republicans said they were willing to work with Democrats on enshrining the principle of net neutrality in legislation. But they wanted to also ensure that regulatory efforts don't get in the way of innovation and quickly evolving internet services.

Sen. John Thune, R-South Dakota, said the internet thrived long before the Obama administration stepped in with rules in 2015, and he predicted that when the FCC repeal is in place, consumers won't notice a change in their service.

"That's what we're going back to: rules that were in place for two decades under a light-touch regulatory approach that allowed the internet to explode and prosper and grow," Thune said.

But the FCC's move has stirred fears among consumer advocates that cable and phone giants will be free to block access to services they don't like or set up "fast lanes" for preferred services — in turn, relegating everyone else to "slow lanes."

Net neutrality opponents have argued market competition would dissuade internet service providers from abusing their power and that consumers would wind up picking which package of features work best for them.

Eliminating net neutrality rules would potentially allow providers to market cheaper, limited plans with access to only a handful of particular websites or offering no-charge connections to certain apps or streaming services.

But Kennedy noted that 22 percent of Louisianans — and 19 percent of Americans overall — have only one choice for broadband internet service. That’d leave roughly one-fifth of Americans no alternative if their current providers began blocking or slowing their connections to some websites.

“This vote comes down to one thing and one thing only — the extent to which you trust your cable company,” Kennedy said.

Kennedy had remained tight-lipped about how he might vote on the net neutrality issue, insisting up until Wednesday morning that he was still studying the issue and making up his mind. “Well, you’ll find out in about five minutes,” Kennedy told inquiring reporters as he headed into the Senate chamber to cast his vote.

His potential swing vote made Kennedy the object of intense lobbying and pressure campaigns from advocates on both sides of the issue.

In recent months, Republicans have used the tools made available in the Congressional Review Act to overturn several environmental, health and safety rules put into place in the final months of the Obama administration. This time, however, it was Democrats who led the effort to kill a rule supported by the Trump administration.

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Kennedy, the former longtime Louisiana state treasurer who arrived in the Senate in 2017, also broke with his party on another Congressional Review Act effort last fall, voting to keep a Consumer Financial Protection Bureau rule making it easier for bank customers to file class-action lawsuits. The GOP-led effort to scrap that rule ultimately succeeded.

The Associated Press contributed to this report.

Follow Bryn Stole on Twitter, @BrynStole.