Last Friday, Sen. Elizabeth Warren (D-MA) announced a plan to break up big tech companies like Facebook and Google, spurring a larger discussion about competition in tech among Democratic presidential candidates.

Over the past few days, Sen. Amy Klobuchar (D-MN), Julían Castro, and other candidates have responded to Warren’s proposal. Some agreed with her move; others have offered different solutions. She’s succeeded in forcing antitrust enforcement into the current policy discussion in Washington, and it’s beginning to catch fire with Republicans as well.

Even Sen. Ted Cruz (R-TX) offered a degree of support for Warren after Facebook took down several of her campaign ads. “She’s right — Big Tech has way too much power to silence Free Speech,” he wrote in a tweet. “They shouldn’t be censoring Warren, or anybody else. A serious threat to our democracy.”

First time I’ve ever retweeted @ewarren But she’s right—Big Tech has way too much power to silence Free Speech. They shouldn’t be censoring Warren, or anybody else. A serious threat to our democracy. https://t.co/VoesOKSqhA — Ted Cruz (@tedcruz) March 12, 2019

Beyond Warren, a majority of the other presidential candidates have agreed with at least the premise of her proposal. In the days since, other candidates have come out with their own ideas and proposals for regulating these companies as well.

Here’s what the top presidential candidates have (or haven’t) said about antitrust following Warren’s proposal.

Sen. Bernie Sanders (I-VT)

Sen. Sanders has a lot in common with Warren, and the two have worked together frequently in the Senate. He has yet to make any public comments on Warren’s proposal. However, he did lead an effort in Congress last year to force Amazon to increase its minimum wage for workers. The campaign eventually succeeded, and Amazon agreed to pay its workers more last fall.

Following Warren’s announcement, Sanders kicked up his criticism of the e-commerce giant, tweeting: “Amazon must recognize that workers’ rights don’t stop at the minimum wage. Amazon must significantly improve working conditions at its warehouses and respect the constitutional right of its employees to form a union and bargain collectively for a better life.”

Sen. Kamala Harris (D-CA)

Sen. Harris has so far abstained from taking any specific position regarding Warren’s proposal or antitrust enforcement in the tech sector. However, throughout her time in the Senate, she has proved to be a tough voice on data privacy, election security, and hate speech on social media platforms like Facebook and Twitter.

Sen. Cory Booker (D-NJ)

Sen. Booker hasn’t commented on Warren’s proposal yet, but he’s been a frequent critic of corporate consolidation for years. In 2017, Booker appeared on the Recode Decode podcast and criticized Amazon’s acquisition of Whole Foods.

Booker said he was worried the merger would cut jobs and reduce pricing competition, particularly in urban areas where “we’re having a hard enough time” getting supermarkets to move in already. “So I am skeptical of this particular merger, highly skeptical of it,” Booker said. “I believe this consolidation as well as other consolidations, we should be holding a far higher bar than we are when we approve these.”

Booker also criticized antitrust enforcement at large in an Open Market Institute speech last October. He called on the Justice Department and the Federal Trade Commission to do a “comprehensive review” of completed mergers to see whether the “promises and predications” made actually played out. If they didn’t, he said, they should “take aggressive action when it’s needed, because our very liberty is at stake.”

Sen. Amy Klobuchar (D-MN)

Sen. Klobuchar was one of the only candidates for president who mentioned issues like data privacy and net neutrality in her official campaign announcement. In February, she introduced legislation that would “modernize” antitrust enforcement and pivot back to the competition model that regulators upheld prior to the 1980s.

“We’ve got to look carefully at all of these deals,” Klobuchar said at SXSW.

Instead of commenting directly on Warren’s proposal, Klobuchar offered a separate option to tax tech companies when they either exploit, sell, or give user data to third-party sources. The plan wasn’t fully fleshed out, but a similar digital services tax has been discussed in the European Union. Last October, the UK Chancellor announced a 2 percent tax on the revenues of companies like Amazon, Facebook, and Google.

Rep. Tulsi Gabbard (D-HI)

Rep. Gabbard responded to Warren’s proposal in a tweet saying that she had plans to propose a similar measure in the House. It’s unclear whether Warren is planning to introduce legislation this congressional term while she’s a senator or wait until the 2020 elections.

Absolute power corrupts absolutely. I agree with Senator Warren on the need to break up big tech companies like Facebook, Google, Amazon. Will be introducing similar legislation in U.S. House. https://t.co/OrdOqH0ZFB — Tulsi Gabbard (@TulsiGabbard) March 12, 2019

Pete Buttigieg (D), Mayor of South Bend, Indiana

Buttigieg said that there’s “no question” US regulators have avoided their responsibility when it comes to policing tech platforms and their market power.

“In some ways these are monopoly problems and market problems that even though they’re associated with tech, [they’re] almost old-fashioned in their nature,” Buttigieg said in an interview with Axios.

When pressed about Warren’s proposal directly, Buttigieg said that the concentration of market control should “set off alarms.” But he also said he was concerned about other issues, like data ownership and privacy, that involve tech giants but aren’t necessarily covered by Warren’s proposal. “There’s a whole set of other issues that are less in the antitrust bucket,” he said.

Julián Castro (D), former HUD Secretary and mayor of San Antonio

Julian Castro said that Warren’s plan was “worth considering.” However, he focused his comments more specifically toward antitrust enforcement at large and the power held by major tech companies without going into much detail.

“I agree that we have to be much stronger in terms of antitrust enforcement,” he said. “I believe that we need to ask a lot more of people at the top in this country, and of wealthy corporations. I don’t understand how Amazon made $11 billion in profit last year, paid no federal taxes, and at the same time, New York was about to offer them a $3 billion package to locate their second headquarters.”

John Hickenlooper (D), former Colorado governor

John Hickenlooper came out positioning himself as a centrist when he announced his presidential bid, but he’s also leaned into strengthening the enforcement of antitrust laws.

“Right now it seems like we say, well, if we get down to [two or three] competitors, that’s a competitive system. That’s probably nonsense,” Hickenlooper said.

He also said he’d like to see antitrust focus go beyond the tech giants. “What are the benefits to society when you have mergers of really large companies like these? Not just tech companies, but banks? It’s in what we call ‘value capture,’” he said. “It’s the companies saying: Well, we don’t need two HR teams, we’ll lay these people off.”

Sen. Kirsten Gillibrand (D-NY)

Sen. Gillibrand has yet to comment on the issue. However, she did criticize Amazon’s attempt to build a headquarters in the Long Island City neighborhood of New York City. The day after Amazon’s announcement, Gillibrand responded saying, “One of the wealthiest companies in history should not be receiving financial assistance from the taxpayers while too many New York families struggle to make ends meet.”