President Trump signed an executive order Thursday aimed at increasing the ability of the government to regulate social media platforms, a marked escalation of his lengthy feud with Silicon Valley over allegations of anti-conservative bias.

The brunt of the order is focused on Section 230 of the Communications Decency Act, a 1996 law that gives platforms legal immunity for content posted by third-party users while also giving them cover to make good-faith efforts to moderate their platforms.

Trump's order directs an agency within the Commerce Department to file a petition with the Federal Communications Commission (FCC) to clarify the scope of Section 230, a proposition that has already drawn rebukes from the two Democratic members of the five-person commission.

Another section of the order would encourage federal agencies to review their spending on social media advertising.

Trump, joined by Attorney General William Barr, addressed reporters in the Oval Office on Thursday afternoon before signing the executive order.

"We're here today to defend free speech from one of the greatest dangers it has faced in American history, frankly, and you know what's going on as well as anybody. It's not good," Trump told reporters.

The president accused social media companies of having “unchecked power to censure, restrict, edit, shape, hide, alter virtually any form of communication between private citizens or large public audiences.” He also said that if he were able to shut Twitter down, he would.

Trump and Barr indicated that legislation on Section 230 could be coming soon in Congress. Barr did not provide further details, while Trump suggested they could just "remove or totally change 230."

When asked about the possibility of a legal challenge to the order, Trump said, “I guess it’s going to be challenged in court, but what isn’t?”

FCC Chairman Ajit Pai said in a statement that the commission "will carefully review any petition for rulemaking filed by the Department of Commerce."

"This debate is an important one," he added.

Another section of the order would direct complaints about alleged political bias on platforms to the Federal Trade Commission and encourage the agency to review whether they constitute “unfair or deceptive business practices.”

The Trump administration created a tool last year for reporting claims of bias on social media platforms.

The White House first acknowledged vague plans for the executive order on Wednesday evening. Officials worked to finalize the details over the following day, as a draft version leaked out that closely lined up with the final order.

The executive order follows a multiday feud between the president and Twitter, the president's favored social medial platform. Twitter on Tuesday applied a label to one of the president's tweets for the first time. The warning, urging users to "get the facts about mail-in ballots," was attached to two posts in which Trump railed against mail-in voting in California, claiming without evidence that the practice is full of fraud.

Trump pounced on the fact check, accusing the company of bias against conservatives.

Trump said Twitter was "stifling FREE SPEECH" and then threatened to “close” social media platforms in a series of posts on the platform.

Since then, Twitter has placed similar labels on hundreds of tweets from a variety of figures across the political spectrum.

The central thesis of Trump’s criticism of social media platforms — that they make content moderation decisions based on anti-conservative bias — has not been substantiated.

Trump has yet to comment on efforts from some of his supporters in Congress to overhaul the 1996 law.

Sen. Josh Hawley (R-Mo.) and Rep. Matt Gaetz (R-Fla.) on Wednesday both announced separately that they are working on legislation to strip Twitter of its liability protections.

Sen. Ted Cruz (R-Texas), a frequent critic of big tech companies for alleged bias, praised the president’s action on Thursday.

“This executive order is an important acknowledgement that we can no longer afford to let Big Tech go unchecked,” he said. “For too long, social media platforms like Twitter have hid behind their opaque algorithms and Section 230 immunity to target speech with which they disagree and advance their own political agendas.”

Democratic lawmakers criticized the order.

Sen. Richard Blumenthal (D-Conn.) called the order “egregiously excessive with clearly malevolent intent to suppress free speech.”

“This is a sad distraction,” Sen. Mark Warner (D-Va.) tweeted. “At a time when common sense regulation of these dominant companies is desperately needed, the President is threatening retaliation if they try to reign in the disinformation, targeted harassment, and voter suppression taking place on their platforms."

Industry groups roundly criticized the order.

Gary Shapiro, president and CEO of the Consumer Technology Association, which represents over 2,000 tech companies including Facebook and Google, called Trump's move "unconstitutional" and "ill-considered."

"The free speech protections in Section 230 of the Communications Decency Act are the legal underpinning of our vibrant U.S. online economy and our nation's global digital leadership. America's internet companies lead the world and it is incredible that our own political leaders would seek to censor them for political purposes," he said in a statement.

The U.S. Chamber of Commerce, which is typically aligned with Republicans, issued a statement sharply criticizing the president's order.

"We believe that free speech and the right to engage in commerce are foundational to the American free enterprise system. Regardless of the circumstances that led up to this, this is not how public policy is made in the United States. An executive order cannot be properly used to change federal law," the Chamber said.

Facebook criticized Trump's move to limit section 230, arguing it would end up restricting online speech

"We believe in protecting freedom of expression on our services, while protecting our community from harmful content including content designed to stop voters from exercising their right to vote," a Facebook spokesperson told The Hill.

"Repealing or limiting section 230 will have the opposite effect. It will restrict more speech online, not less," the spokesperson said. "By exposing companies to potential liability for everything that billions of people around the world say, this would penalize companies that choose to allow controversial speech and encourage platforms to censor anything that might offend anyone."

Google, which owns YouTube, has not publicly responded to Trump's order.

A Twitter spokesman called the move "a reactionary and politicized approach to such a landmark law."

"Section 230 protects American innovation and freedom of expression, and it’s underpinned by democratic values. Attempts to unilaterally erode it threaten the future of online speech and Internet freedoms."

Lawmakers have attempted to make changes to the legal protections afforded under Section 230, but for reasons other than allegations of political bias.

In March, a bipartisan coalition of 11 senators introduced legislation that would strip 230 protections from tech companies that fail to adopt best practices to address child sexual exploitation content on their platforms. The measure faced opposition from tech advocates and has been sidelined during the coronavirus pandemic.

Blumenthal, who is a cosponsor of the legislation, said Trump's order is misguided and takes aim at the wrong issue.

“Whatever the criticisms I may have of current law, Trump’s demagogic meat-ax Executive Order is exactly wrong,” he said in a statement. “This Executive Order is an authoritarian attack against freedom of expression and accountability. It provides no relief to the countless children, victims of human trafficking, and others who have suffered real harms by Big Tech.”

Updated at 7:12 p.m.