Speaking at a Sanders rally in Iowa on Friday night, the Oscar-winning documentarian tore into the DNC's decision.

"They removed it so that [Bloomberg] could be in the next debate," Moore said about the donor requirement. "He doesn't have to show that he has any support amongst the American people. He can just buy his way onto the debate stage!"

He continued, "And I've got to tell you what's so disgusting about this: I watched the debate here in Iowa two weeks ago, the all-white debate. And the fact that the DNC will not allow Cory Booker on that stage, will not allow Julián Castro on that stage, but they’re going to allow Mike Bloomberg because he has a billion f---ing dollars!"

Watch:

Moore then declared, "I'm sorry, those days are over!"

That sparked roars and cheers from the Sanders supporters.

In addition, other 2020 Democratic presidential candidates took to social media to slam the DNC's decision, sparking the hashtag "#DNCRigging" to trend on Twitter.

"The DNC didn’t change the rules to ensure good, diverse candidates could remain on the debate stage. They shouldn’t change the rules to let a billionaire on. Billionaires shouldn't be allowed to play by different rules—on the debate stage, in our democracy, or in our government," Sen. Elizabeth Warren, D-Mass., wrote.

The DNC didn’t change the rules to ensure good, diverse candidates could remain on the debate stage. They shouldn’t change the rules to let a billionaire on. Billionaires shouldn't be allowed to play by different rules—on the debate stage, in our democracy, or in our government.

— Elizabeth Warren (@ewarren) January 31, 2020

"The DNC changing its debate criteria to ignore grassroots donations seems tailor-made to get Mike Bloomberg on the debate stage in February. Having Americans willing to invest in your campaign is a key sign of a successful campaign. The people will win out in the end," Andrew Yang similarly stated.

The DNC changing its debate criteria to ignore grassroots donations seems tailor-made to get Mike Bloomberg on the debate stage in February. Having Americans willing to invest in your campaign is a key sign of a successful campaign. The people will win out in the end.

— Andrew Yang🧢 (@AndrewYang) February 1, 2020

"Billionaire Bloomberg just bought the @DNC. #PayToPlay," Rep. Tulsi Gabbard, D-Hawaii said.

Billionaire Bloomberg just bought the @DNC. #PayToPlay #StandWithTulsi

— Tulsi Gabbard 🌺 (@TulsiGabbard) January 31, 2020

"When @CoryBooker led an effort to change the debate thresholds, the DNC refused—saying they couldn’t benefit any candidate. It seems the only candidate they’re willing to benefit is a billionaire who’s buying his way into the race. Total mess," former 2020 candidate Castro reacted.

Despite having a late campaign launch, Bloomberg has managed to climb up in national polls, placing in fourth with 8.1 percent according to the Real Clear Politics average. He so far has one out of the four qualifying polls required to earn a spot on the mid-February debate stage.

Meanwhile, the DNC reportedly has other plans in the works "to stop Sanders" at the party's nominating convention in Milwaukee in the summer, Politico reported. The proposed rule changes would give top party officials more influence on deciding the Democratic nominee, the report said.

The article drew pushback from DNC boss Tom Perez.

"Absolutely not," Perez wrote about the "stop Sanders" allegation. "We put in the work to ensure power was returned to the grassroots, we will be following the rules set forth by the DNC. We will not bend on this. We will not change our rules."

But former presidential candidate Marianne Williamson scoffed at Perez's claim that the DNC "put in the work."

"No you didn't," she wrote. "The DNC's job should be to facilitate democracy, not dictate it or manipulate it. You're the modern equivalent of men with cigars in a back room deciding who the candidate will be. We'll win in 2020-not because of but despite the way you've manipulated the process."

Informed of the rule change Friday night, former Vice President Joe Biden said of Bloomberg, “He’s not even on the ballot in Nevada.”

Biden reacts to DNC rule change that means Bloomberg could make the Feb. 19 debate in Nevada – straight to the point:
"HE'S NOT EVEN ON THE BALLOT IN NEVADA!" his face in this close up lmao pic.twitter.com/rcbweViLWM

— Emily Larsen (@emilyelarsen) February 1, 2020

Sen. Corey Booker’s (D-NJ) former campaign manager, Addisu Demissie, tweeted in response to the rule change that among the most significant days on the campaign trail was when the DNC announced a 130,000 donor threshold to qualify for the next debate stage.

“Oh, do you mean the day I literally Control+A+ Deleted a plan for a whole entire early game, early state persuasion strategy and used the money to buy email addresses instead?” former Booker deputy campaign manager Jenna Lowenstein responded. “I don’t remember it. Blacked it out.”

At least one campaign endorsed the change: Bloomberg’s

“We are thrilled that voters could soon have the chance to see Mike Bloomberg on the debate stage, hear his vision for the country, and see why he is the strongest candidate to defeat Donald Trump and bring our country together,” the former New York City mayor’s campaign manager said.