As Iowans prepare to caucus Monday night, angry supporters of Sen. Bernie Sanders charge the Democratic National Committee is up to its old tricks, rigging the primary election in favor of the establishment candidate again.

In 2016, they pointed to the DNC's ambiguous delegate allocation rules and the scheduling of only a few debates, with some at times of low viewership.

Now, the DNC's removal of the requirement that a candidate show grassroots fundraising prowess to be on the debate stage looks like deja vu. The change makes it easier for billionaire Michael Bloomberg to participate in the Nevada debate, the Washington Times reports.

Suspicions are further raised by House Speaker Nancy Pelosi's decision to delay sending the articles of impeachment to the Senate, which has kept the self-proclaimed democratic socialist off the campaign trail for most of the last two weeks.

TRENDING: Americans against unconstitutional mask mandates

The final Emerson College/7 News Iowa poll finds Sanders in the lead going into Monday's caucus, with 28% support. Former Vice President Joe Biden, the apparent establishment choice, is second with 21%. Former South Bend Mayor Pete Buttigieg is at 15%, Sen. Elizabeth Warren, D-Mass., is at 14%, and Senator Amy Klobuchar has 11%.

Sanders nearly won the Iowa caucuses in 2016, challenging Clinton all the way to the Democratic National Convention.

The Democrats' treatment of Sanders four years ago had consequences, according to the Pew Research Center. A survey found 81% of consistent Sanders supporters who voted in the general election chose Sanders. But 11% voted for Green Party candidate Jill Stein or Libertarian nominee Gary Johnson, and 3% supported Trump.

'Sabotage' again

A Sanders supporter who attended a Sanders rally recently in Perry, Iowa, told the Times one doesn't have to be a "conspiracy theorist" to believe something is up.

"There are powers that are trying to sabotage his win again for the presidency, and it is because he has had the same message for the last 40 or 50 years," said Dustin Menke, 42.

"That is why the establishment is afraid of him, because he is not going to back down."

Among Sanders' supporters are far-left freshmen Reps. Ocascio-Cortez of New York, Ilhan Omar of Minnesota and Rashida Tlaib of Michigan.

Another is left-wing filmmaker Michael Moore, who said at a recent campaign rally in the Des Moines suburbs that the DNC is allowing Bloomberg on the debate stage only "because he has a [expletive] dollars."

"Oh, they are so upset. "They are, like, asking each other, 'How the hell did this happen? Bernie wasn't supposed to win," Moore said.

Clinton said in an interview Friday that Sanders bears blame for her loss to Trump.

"All the way up until the end, a lot of people highly identified with his campaign were urging people to vote third party, urging people not to vote," she told the Your Primary Playlist podcast. "It had an impact."

Chris Matthews: Reminds me of McGovern

On Monday morning, MSNBC host Chris Matthews said he's not happy about any of the Democratic candidates, the Washington Examiner reported.

"I think they have to find a candidate for president that can beat Trump," Matthews said.

He said Sanders is "not going to be president, comparing the Vermont senator's campaign to the 1972 presidential election in which Democrats' choice, Sen. George McGovern of South Dakota, won only one state and Washington, D.C., against incumbent Republican President Richard Nixon.

Matthews said McGovern's campaign "feels a lot like" Sanders, noting both "excited the party."

Over the past two weeks, Project Veritas has released undercover video exposing the radical views of paid Sanders campaign organizers. On Tuesday, video was published of a Sanders staffer admitting the campaign attracts anarchists, Marxists and other "truly radical people." He echoed other staffers highlighted by Project Veritas in his call for a "militant" peoples' movement to "strip power" from capitalists.