In a major reversal of existing policy, Twitter CEO Jack Dorsey announced last week that the social media website will ban all political ads later this month.

“We’ve made the decision to stop all political advertising on Twitter globally,” Dorsey tweeted. “We believe political message reach should be earned, not bought.”

Dorsey said political ads pose “new challenges” to civic discourse, including “machine learning-based optimization of messaging and micro-targeting, unchecked misleading information, and deep fakes.” These innovative threats all come at “increasing velocity, sophistication, and overwhelming scale,” Dorsey said.

The policy will be finalized by November 15 and will include a few exceptions, such as ads in support of non-partisan measures like voter registration, Dorsey tweeted. 

The new policy stands in stark contrast with Facebook’s recent exemption of political advertising from fact-checking and removal, which was first announced in late September. A few weeks later, during a speech at Georgetown University, Facebook CEO Mark Zuckerberg said people should have access to all political ads and judge their credibility for themselves, rather than having a “private company” censor politicians and the news.

“We don’t fact-check political ads,” Zuckerberg said. “We don’t do this to help politicians, but because we think people should be able to see for themselves what politicians are saying. And if content is newsworthy, we also won’t take it down even if it would otherwise conflict with many of our standards.”

“I know many people disagree, but, in general, I don’t think it’s right for a private company to censor politicians or the news in a democracy,” he continued. “And we’re not an outlier here. The other major internet platforms and the vast majority of media also run these same ads.”

With Dorsey’s announcement, Twitter’s roughly 330 million monthly active users will no longer be targeted with political ads. Of those, about 68 million users are in the United States.

According to Cat Zakrzewski, a technology reporter at The Washington Post, the new policy highlighted Dorsey’s rebuke of the “free expression” argument that Zuckerberg used to justify Facebook’s policy in the past.

“This isn’t about free expression,” Dorsey wrote in his announcement. “This is about paying for reach. And paying to increase the reach of political speech has significant ramifications that today’s democratic infrastructure may not be prepared to handle.”

NEW: Mark Zuckerberg just dined with civil rights leaders hoping to change his mind on political ads, w/@tonyajoriley in The Technology 202: https://t.co/NgVElysOMl

— Cat Zakrzewski (@Cat_Zakrzewski) November 5, 2019

In the face of growing opposition to Facebook’s policy, Zuckerberg dined with civil rights leaders on Monday night and listened to their concerns that politicians would exploit the lax policy to spread disinformation, Zakrzewski reported.

“I am now hopeful about the fact that he was open to the discussion and seemed to be going through a process of trying to get it right,” Al Sharpton, president of the National Action Network, told Zakrzewski. “I’m not where we want to be, but better than where we were.”

The stark difference in policy is a new phase in the “long-running feud” between Facebook and Twitter, Zakrzewski wrote.

Dipayan Ghosh, co-director of the Platform Accountability Project at Harvard Kennedy School, told Zakrzewski that Dorsey, “like many others, is fed up with [Facebook].”

“Some of it might be commercially driven, but most all of it is that [Dorsey] is upset about the nature of Facebook and its insidious effect on political circumstances in this country,” Ghosh, who previously worked on global privacy at Facebook, said.

Reactions to the new policy were split across partisan lines. While Democrats supported Dorsey’s move, Republicans were critical of the ban on political ads.

Former presidential candidate Hillary Clinton applauded Dorsey’s decision and shined the spotlight back on to Zuckerberg, tweeting, “This is the right thing to do for our democracy in America and all over the world. What say you, @Facebook?” 

Republicans also took to Twitter to voice their opinions. Brad Parscale, the president’s campaign manager, slammed the new policy as a “very dumb decision.”

“Will Twitter also be stopping ads from biased liberal media outlets who will now run unchecked as they buy obvious political content meant to attack Republicans?” Parscale asked. “This is yet another attempt to silence conservatives, since Twitter knows President Trump has the most sophisticated online program ever known.”

Meanwhile, Sen. Ted Cruz, R-Texas, wrote an op-ed in The Hill in support of Zuckerberg’s policy. He criticized the “far left wing of the Democratic Party” for siding with Twitter’s policy because they would rather urge “Big Tech to simply make it impossible for anyone to disagree,” than “engage in a thoughtful discussion based on facts, reason, and evidence.” 

Cruz argued the new policy will favor incumbents who have the funds to rely on other, more expensive forms of advertising. He also highlighted the ramifications for private citizens, as a result of the ban.

“What Jack Dorsey is proposing is to stop you, individually, or in a group—whether it be the Sierra Club, the NRA, Planned Parenthood, AIPAC, or a totally new not-for-profit group trying to advocate for a particular idea—from being able to speak actively about public policy,” Cruz wrote.