From taxing wealth to student loan cancellation and a Green New Deal, subjects that did not gain much traction in the 2016 primary have come to be policy flashpoints in the crowded field of 23 candidates.

One such issue has been the question of whether to break up Facebook.

Sen. Elizabeth Warren led the charge by releasing an ambitious plan on March 8 calling for the breakup of the social media giant, along with Amazon and Google. She called for WhatsApp and Instagram to be spun off from Facebook.

She has since been joined by Sen. Bernie Sanders and Rep. Tulsi Gabbard in calling for the breakup of Facebook. And other candidates in recent days have expressed skepticism about the tech giant, following Facebook co-founder and 2008 Obama campaign organizer Chris Hughes’ publication of an op-ed in the New York Times on May 9 calling for the government to break up the social-media platform.

Sarah Miller, deputy director of the Open Markets Institute, a Washington anti-monopoly think-tank, said that the speed at which Facebook has become a campaign issue has been remarkable.

“There has been a consensus built on this incredibly fast, faster than I would have imagined, given how popular Facebook was two or three years ago in Washington,” she told Fortune. She added that economic concentration and antitrust began to gain attention at the same time as Facebook experienced multiple scandals, which outraged “a range of different groups across the ideological spectrum.”

Other candidates have sounded more skeptical about Facebook but without actually calling for its breakup.

Former Vice President Joe Biden told the Associated Press on May 13 that breaking up Facebook is “something we should take a really hard look at.”

Sen. Kamala Harris, who represents Silicon Valley as a California senator, also said that it was worth “seriously” looking into, and called the company “essentially a utility that has gone unregulated.”

Miller, however, said, “I don’t think that ‘saying we should look at it’ should be satisfying, and that to me doesn’t show leadership.”

Nevertheless, their positions represent a change in the center of gravity for Democratic candidates, who have historically relied on cash from the technology industry to help fund their campaigns.

President Barack Obama praised Facebook as a place where he could have “dialogue” with voters in 2011, but since Trump won a surprise election with the help of the platform, it has come to public attention that Facebook can spread misinformation, be used by foreign actors such as the Russian government-linked Internet Research Agency, and its massive user data can be harvested by firms hired by campaigns to target voters.

More candidates have not embraced Warren’s plan and have gone as far as to criticize it. South Bend, Ind., Mayor Pete Buttigieg has said he “potentially” favors breaking up Facebook, but has shied away from outright endorsing Warren’s plan and has courted financial support from Silicon Valley.

Sen. Cory Booker, who has close ties to Silicon Valley, went a step further and rejected Warren’s plan as a “Trump thing to say”— making clear that he wasn’t comparing them personally—but warned of the “ill effects” of “corporate consolidation,” which he said should be left up to the Justice Department to regulate.

Former Rep. Beto O’Rourke said he favored regulation of Facebook over a breakup.

Miller said that regulation was important, but it alone would not solve the problem.

“If you allow Facebook to retain its market dominance, it will be dangerous in a lot of ways, it will be able to evade regulation, and continue to crowd out any competitors,” she told Fortune.

Facebook has rejected calls for its breakup, claiming in a Times op-ed responding to Hughes that it was being punished for its success.

“Success should not be penalized. Our success has given billions of people around the globe access to new ways of communicating with one another,” wrote Nick Clegg, vice president for global affairs and communications for the company.

Still, with an expected $5 billion fine to be announced by the Federal Trade Commission soon over the company’s privacy violations, questions will remain in the 2020 race over whether that punishment is really substantial enough for a company with $56 billion in annual revenue, or whether the Justice Department should move to break up Facebook’s constituent parts.

“We are a nation with a tradition of reining in monopolies, no matter how well intentioned the leaders of these companies may be. Mark’s power is unprecedented and un-American,” wrote Hughes, the Facebook co-founder, in the Times, referring to Facebook founder Mark Zuckerberg.

With the first Democratic debates happening in late June, it may well not be too long before candidates are asked onstage point-blank whether they agree with Hughes’ call to break up Facebook.