The policy outlines how the changes will apply to the political sphere and defines political content as content that references candidates, political parties, elected or appointed government officials, elections, referendums, ballot measures, legislation, regulation, directive, judicial outcome or fundraising. The ban also explicitly blocks super PACs and 501(c)(4)s.
Twitter announced will no longer allow political ad on the platform last month.
"We believe political message reach should be earned, not bought," Dorsey tweeted, along with a number of additional tweets explaining the reasons why.
"While internet advertising is incredibly powerful and very effective for commercial advertisers, that power brings significant risks to politics, where it can be used to influence votes to affect the lives of millions," Dorsey wrote. "Internet political ads present entirely new challenges to civic discourse: machine learning-based optimization of messaging and micro-targeting, unchecked misleading information, and deep fakes. All at increasing velocity, sophistication, and overwhelming scale."
"We considered stopping only candidate ads, but issue ads present a way to circumvent. Additionally, it isn’t fair for everyone but candidates to buy ads for issues they want to push. So we're stopping these too," Dorsey added.
Among the 2020 Democratic field, former Vice President Joe Biden's campaign was one of the first to applaud the move.
"We appreciate that Twitter recognizes that they should not permit disproven smears, like those from the Trump campaign, to appear in advertisements on their platform," said Bill Russo, the Biden campaign's deputy communications director in a statement. "It would be unfortunate to suggest that the only option available to social media companies to do so is the full withdrawal of political advertising, but when faced with a choice between ad dollars and the integrity of our democracy, it is encouraging that, for once, revenue did not win out."
Another Democratic hopeful, Montana Gov. Steve Bullock, turned the attention to another social media giant, tweeting, "Good. Your turn, Facebook."
But the effect of Twitter's move might not be as impactful as if Facebook followed suit. For example, while the Trump campaign is spending $15.6 million on Facebook ads and $9.1 million on Google ads since January, they have only spent $6,300 on Twitter ads.
Trump campaign communications director, Tim Murtaugh, told ABC News that the campaign planned to spend "many" millions over the next 12 months on the platform, after shutting down their Twitter ads back in August.
Twitter CFO Ned Segal also acknowledged on on Twitter, "political ad spend for the 2018 US midterms was <$3M."
The final policy will be shared on Nov. 15 and will go into effect on Nov. 22, Dorsey said, noting there will be a "few exceptions" including ads that support voter registration.
"This isn’t about free expression. 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. It’s worth stepping back in order to address," Dorsey concluded.
Dorsey's announcement is a striking contrast from Facebook's standing policy, which virtually gives advertisers free reign on the platform to spread disinformation in political ads, amid rising concerns over the influence of social media on voters ahead of the 2020 election.
Not long after Dorsey made the announcement about political ads. Zuckerberg posted about Facebook's political ad policy.
"Right now, the content debate is about political ads. Should we block political ads with false statements? Should we block all political ads? Google, YouTube and most internet platforms run these same ads, most cable networks run these same ads, and of course national broadcasters are required by law to run them by FCC regulations," he wrote on Facebook.
"I don't think it's right for private companies to censor politicians or the news ... And it's hard to define where to draw the line. Would we really block ads for important political issues like climate change or women's empowerment? Instead, I believe the better approach is to work to increase transparency. Ads on Facebook are already more transparent than anywhere else. We have a political ads archive so anyone can scrutinize every ad that's run -- you can see every message, who saw it, how much was spent -- something that no TV or print media does," he continued.
He also denied that Facebook's political ad policy was about making money. "Some people accuse us of allowing this speech because they think all we care about is making money. That's wrong. I can assure you, from a business perspective, the controversy this creates far outweighs the very small percent of our business that these political ads make up. We estimate these ads from politicians will be less than 0.5% of our revenue next year. That's not why we're doing this," he wrote.
Last week, Facebook CEO Mark Zuckerberg was grilled on Capitol Hill as he defended the social media giant's controversial policy about not fact-checking most political ads before lawmakers.
In his congressional testimony, Zuckerberg said his company would not engage in any censorship or fact-checking of political ads - and when pressed by several Democratic committee members, the tech-giant founder argued, "We believe in a democracy, it is important that people can see for themselves what politicians are saying."
One of the tensest exchanges for Zuckerberg came when Congresswoman Alexandria Ocasio-Cortez, D-N.Y., questioned him about Facebook's fact-checking policy, and underscored a key flaw in their stance on Freedom of Speech.
"I just want to know how far I can push this in the next year," Ocasio-Cortez said. "Under your policy using census data as well, could I pay to target black zip codes and advertise them the incorrect election date?"
Zuckerberg said, "No."
"Could I run ads targeting Republicans in primaries saying they voted for the Green New Deal?" she asked. In the hearing room, he replied that he did not know the answer.
But the tension between Facebook and Washington goes beyond the halls of Congress -- as several 2020 presidential candidates have scolded the social network site for their policies.
Earlier this month, Sen. Elizabeth Warren, D-Mass., intentionally ran a paid Facebook ad with a completely false claim about Zuckerberg endorsing Trump for president, in order to show how an individual can exploit Facebook's policy and lie to a universe of social media users.
In early October, the Biden campaign sent a letter to Facebook asking to remove a false ad, run and paid for by President Trump's campaign, but Facebook denied their request because the company said it does not violate company policies.
"Our approach is grounded in Facebook's fundamental belief in free expression, respect for the democratic process, and the belief that, in mature democracies with a free press, political speech is already arguably the most scrutinized speech there is. Thus, when a politician speaks or makes an ad, we do not send it to third-party fact checkers," Katie Harbath, public policy director, Global Elections for Facebook wrote.
ABC News' John Verhovek, Will Steakin and MaryAlice Parks contributed to this report.