PHOTO: CNN
Now playing
01:11
Elizabeth Warren: I'm not taking a dime of PAC money
Adam Kinzinger Zeleny dnt 03082021
PHOTO: CNN
Adam Kinzinger Zeleny dnt 03082021
Now playing
04:25
'Could be a kamikaze mission': GOP lawmaker takes on Trump
PHOTO: CNN
Now playing
03:09
Governor on relief bill: Why reward states for bad behavior?
PHOTO: CNN
Now playing
03:02
'A ransom demand': Avlon slams Trump's letter to RNC
PHOTO: CNN
Now playing
01:26
Sen. Joe Manchin explains why he wanted changes to relief bill
Now playing
02:29
MS gov. encourages residents to wear masks despite dropping mandate
Now playing
01:21
Lawmaker fires back at Tucker Carlson's QAnon spin
Sen. Lisa Murkowski (R-AK) asks a question at a hearing of the Senate Health, Education, Labor and Pensions Committee on September 23, 2020 in Washington, DC.
PHOTO: Alex Edelman/Pool/Getty Images
Sen. Lisa Murkowski (R-AK) asks a question at a hearing of the Senate Health, Education, Labor and Pensions Committee on September 23, 2020 in Washington, DC.
Now playing
01:40
Trump plans to campaign against Sen. Murkowski in 2022
Biden 03062021
PHOTO: CNN
Biden 03062021
Now playing
02:28
'Help is on the way': Biden speaks after Senate passes relief plan
Now playing
03:04
Schumer: Nobody said it would be easy, but it is done
01 senate stimulus bill 210306
PHOTO: Senate TV
01 senate stimulus bill 210306
Now playing
01:47
Senate passes Biden's $1.9 trillion Covid-19 relief bill
WASHINGTON, DC - MARCH 05: Sen. John Cornyn (R) (R-TX) talks with Sen. Joe Manchin (D-WV) while walking to the U.S. Senate chamber for a vote March 05, 2021 in Washington, DC. The Senate continues to debate the latest COVID-19 relief bill.  (Photo by Win McNamee/Getty Images)
PHOTO: Win McNamee/Getty Images
WASHINGTON, DC - MARCH 05: Sen. John Cornyn (R) (R-TX) talks with Sen. Joe Manchin (D-WV) while walking to the U.S. Senate chamber for a vote March 05, 2021 in Washington, DC. The Senate continues to debate the latest COVID-19 relief bill. (Photo by Win McNamee/Getty Images)
Now playing
02:54
Axelrod breaks down Manchin's surprising move
sinema
PHOTO: CNN
sinema
Now playing
01:50
Senator's move has many on the internet outraged
PHOTO: FBI
Now playing
02:58
Trump State Department official charged in Capitol riot
WASHINGTON, DC - JANUARY 06: U.S. Sen. Paul Gosar (R-AZ) speaks on the floor of the House Chamber during a joint session of congress on January 06, 2021 in Washington, DC. Congress held a joint session today to ratify President-elect Joe Biden's 306-232 Electoral College win over President Donald Trump. A group of Republican senators said they would reject the Electoral College votes of several states unless Congress appointed a commission to audit the election results. (Photo by Drew Angerer/Getty Images)
PHOTO: Drew Angerer/Getty Images
WASHINGTON, DC - JANUARY 06: U.S. Sen. Paul Gosar (R-AZ) speaks on the floor of the House Chamber during a joint session of congress on January 06, 2021 in Washington, DC. Congress held a joint session today to ratify President-elect Joe Biden's 306-232 Electoral College win over President Donald Trump. A group of Republican senators said they would reject the Electoral College votes of several states unless Congress appointed a commission to audit the election results. (Photo by Drew Angerer/Getty Images)
Now playing
02:19
This is what Rep. Gosar was posting days before Capitol riot
John King Magic Wall 0305
PHOTO: CNN
John King Magic Wall 0305
Now playing
02:17
President Biden sending a team to the US-Mexico border
(CNN) —  

Sen. Elizabeth Warren on Tuesday challenged her Democratic primary rivals to release the names of contributors and fundraisers with influential positions on their campaigns, while pledging to champion legislation that would effectively disqualify big-dollar donors from being appointed to cushy diplomatic posts.

The requests were written into a series of mostly new proposed campaign finance restrictions, which would ban corporate PACs from donating to federal candidates and make it illegal for certain super PACs to be run by operatives with professional or personal ties to the candidate they’re backing.

Now firmly among the front-runners for the Democratic presidential nomination, Warren has increasingly centered her campaign on a broad anti-corruption platform. In past rollouts, she promised to forbid lobbyists from making political contributions, acting as bundlers or hosting fundraisers for candidates. Former top federal officials – including presidents, vice presidents, members of Congress, judges, and cabinet secretaries – would also be permanently prohibited from taking lobbying jobs.

While Warren does not name any of her competitors in her Medium post, the new call for campaigns to “disclose any donor or fundraiser who has a special title on their campaign, including national and regional finance committee members and bundler designations” is an apparent nudge to a number of top rivals, like former Vice President Joe Biden, South Bend, Indiana, Mayor Pete Buttigieg and California Sen. Kamala Harris, who all regularly attend big-dollar fundraising events.

Warren’s call to cut off the donor-to-ambassador pipeline, which she acknowledges has been common practice in both Republican and Democratic administrations, comes with increased resonance now that President Donald Trump’s EU ambassador, Gordon Sondland, a Republican megadonor who gave $1 million to Trump’s inaugural committee, has emerged as a key figure in the Ukraine scandal.

Sondland got tied up in the ongoing congressional impeachment inquiry after the disclosure of his text messages with Bill Taylor, a career diplomat serving as the charge d’affaires at the US Embassy in Kiev, in which Taylor questions why Trump is withholding “security assistance” to the Ukrainian government.

For decades, administrations of both political parties have appointed big donors and bundlers to ambassadorial posts around the world,” Warren writes. “My plan will make it the law by prohibiting campaign donations and political spending from being a consideration in the selection of an ambassador.”

Warren also used the new round of proposals to further explain the parameters of her campaign’s self-imposed fundraising rules. Last week, she said for the first time that her primary strategy of refusing to solicit wealthy donors and hold big-dollar fundraisers will extend into the general election if she were to become the nominee.

She previously disavowed federal lobbyist and PAC money and put a cap on contributions she receives from fossil fuel and big pharmaceutical executives. In the plan released Tuesday, Warren broadens those restrictions, writing, “I’m not going to take any contributions over $200 from executives at big tech companies, big banks, private equity firms, or hedge funds.”

A Warren aide told CNN the new rule would be “retroactive” and said, “We will identify anyone who would fall under this policy for the presidential campaign and will plan to return those contributions.”

Amid her feud with Facebook over the social media giant’s advertising policy, which exempts posts by candidates from third-party fact-checking, Warren is also proposing to “modernize campaign finance law for the digital age.”

Online political ads would, according to Warren’s proposal, be regulated more like those run on television and radio, forcing “large platforms” like Facebook to keep “to keep a ‘political file’ with information about ad buys.” Warren also calls for those companies to make a “reasonable” attempt to seek out and reject “illegal ad buys by foreign nationals.”

Meanwhile, Warren would expand disclosure requirement for super PACs and other dark money groups that grew up out of the Supreme Court’s Citizens United decision, while reducing individual contribution caps and established a 6-1 matching funds program on all donations less than $200.

The Massachusetts senator also addresses the quadrennial influx of corporate cash to both major parties’ national conventions, proposing to make them publicly funded. That follows Sen. Bernie Sanders’ pledge last week to put a stop on all corporate contributions to the 2020 Democratic National Convention if he becomes the nominee.

This story has been updated.