Florida Governor Ron DeSantis has signed a first-in-the-nation bill that can penalise tech companies for deplatforming politicians.
The legislation states that platforms can only suspend accounts for 14 days, and will be fined as much as $250,000 (£176,000) per day for violations.
NetChoice, a tech lobbying group whose members include Twitter and Facebook, testified against the bill in March.
The bill, believed to be the first of its kind, will take effect on 1 July.
Mr DeSantis has been vocal about Big Tech, arguing that platforms such as Twitter, Facebook and YouTube are silencing conservative voices.
Earlier this year, he said Big Tech had “come to look more like Big Brother”.
Legal challenges are expected, with opponents contending that the bill violates Americans’ constitutional rights to free speech.
Critics also say the new law could have unintended consequences.
In March, Steve DelBianco, NetChoice’s chief executive, said while testifying against the bill: “Imagine if the government required a church to allow user-created comments or third-party advertisements promoting abortion on its social media page.
“Just as that would violate the First Amendment [guaranteeing the right to free speech], so too does [this bill] since it would similarly force social media platforms to host content they otherwise would not allow.”
Former US President Donald Trump was banned by Twitter and Facebook and suspended by YouTube after the Capitol Hill riot in January.
Earlier this month, Facebook’s Oversight Board decided to uphold the platform’s decision, but asked the social network to review the decision within six months.
With Mr Trump barred from multiple platforms, it is unclear what this new Florida law means for any potential comeback for the former president.
Twitter declined to comment. Facebook and YouTube have not responded to the BBC’s request for comment.
Mr Trump spent the first few months of his time after leaving office in Florida. He and Mr DeSantis are seen as ideological bedfellows.
According to the Tampa Bay Times, Mr DeSantis was asked if this bill was meant to help Mr Trump, to which he replied: “This bill is for everyday Floridians.”
Exemptions from the law
The legislation includes a clause that exempts a company “that owns and operates a theme park or entertainment complex”.
Florida is home to the Disney World theme park.
NBC Miami reported some lawmakers saw this as “hypocritical”.
“If Facebook buys a theme park, does that prevent us from being able to regulate what happens on Facebook?” asked Andrew Learned, a Democratic member of Florida’s House of Representatives.
“So, if they bought a theme park and named it Zuckerland and he met the definition of a theme park under Florida statute, then yes,” said Republican Representative Blaise Ingoglia.