FILE - Georgia Republican House candidate Marjorie Taylor Greene endorses Sen. Kelly Loeffler (R-GA) during a press conference on Oct. 15, 2020 in Dallas, Georgia. (Dustin Chambers/Getty Images)
WASHINGTON - Republican Senate leader Mitch McConnell denounced newly elected Rep. Marjorie Taylor Greene on Monday, calling the far-right Georgia Republican's embrace of conspiracy theories and "loony lies" a "cancer for the Republican Party."
"Somebody who’s suggested that perhaps no airplane hit the Pentagon on 9/11, that horrifying school shootings were pre-staged, and that the Clintons crashed JFK Jr.’s airplane is not living in reality," said McConnell, R-Ky. "This has nothing to do with the challenges facing American families or the robust debates on substance that can strengthen our party."
FILE - Mitch McConnell (R-KY) speaks at a news conference with other Senate Republicans at the U.S. Capitol on Dec.15, 2020 in Washington, DC. (Tom Brenner-Pool/Getty Images)
The statement comes as House Democrats are mounting an effort to formally rebuke Greene, who has a history of making racist remarks, embracing conspiracy theories and endorsing violence directed at Democrats. It also puts pressure on House Republican leaders to discipline her.
Democrats have teed up action Wednesday to send a resolution to the House floor that would strip Greene of assignments on the House education and budget committees, if House Minority Leader Kevin McCarthy, R-Calif., doesn’t do so first.
"It is my hope and expectation that Republicans will do the right thing and hold Rep. Greene accountable, and we will not need to consider this resolution," said House Majority Leader Steny Hoyer, D-Md. "But we are prepared to do so if necessary."
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Some Democrats have called for going further and expelling Greene from the House — an unlikely outcome that would require backing from Republicans, since expulsion requires a two-thirds vote. Another option is censure.
Democrats' willingness to act against a member of the opposing party underscores their desire to confront far-right politicians, like Greene, who are closely aligned with some of former President Donald Trump’s fringe supporters, including extremist groups that were involved in the violent Capitol insurrection. It also shines a light on the GOP's reluctance to punish Trump supporters in their ranks for fear of alienating some of the former president's most ardent voters.
"If Republicans won’t police their own, the House must step in," said Rep. Debbie Wasserman Schultz, D-Fla., who is sponsoring the measure to remove Greene from the committees.
In a tweet over the weekend, Greene sounded a defiant tone. She also said she had spoken to Trump and was "grateful for his support."
"I will never back down and will stand up against the never ending blood thirsty mob," she tweeted.
On Monday, she tweeted that Democrats, if they move forward, will come to regret the "precedent they are setting," arguing that it would be "used extensively against members on their side once we regain the majority after the 2022 elections."
Greene's views were in the spotlight even before she joined the House last month.
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The Georgia Republican has expressed support for QAnon conspiracy theories, which focus on the debunked belief that top Democrats are involved in child sex trafficking, Satan worship and cannibalism. Facebook videos surfaced last year showing she’d expressed racist, anti-Semitic and anti-Muslim views. Top Republicans denounced her at the time, hoping to block her from capturing the GOP nomination in her reliably red congressional district in northwest Georgia.
But after she won her primary, they largely accepted her. Since then, even more of her past comments, postings and videos have been unearthed, though many were deleted recently after drawing attention.
She "liked" Facebook posts that advocated violence against Democrats and the FBI. One suggested shooting House Speaker Nancy Pelosi in the head. In response to a post raising the prospect of hanging former President Barack Obama, Greene responded that the "stage is being set."
In an undated video posted online, Greene floated a conspiracy theory that falsely suggests that the 2017 mass shooting that killed 58 people at a country music festival in Las Vegas could have been a false flag operation to build support for gun control legislation.
"How do you get avid gun owners and people that support the Second Amendment to give up their guns and go along with anti-gun legislation?" Greene said in the video. "You make them scared, you make them victims and you change their mindset and then possibly you can pass anti-gun legislation. Is that what happened in Las Vegas?"
She also "liked" a Facebook post that challenged the veracity of a 2012 mass shooting at Sandy Hook Elementary School in Newtown, Connecticut. Another video captured her confronting Parkland school shooting survivor David Hogg.
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Rep. Marjorie Taylor Greene harasses Parkland shooting survivor
Video from 2019 showing Rep Marjorie Taylor Greene haranguing Parkland shooting survivor David Hogg resurfaced in late January.
RELATED: Resurfaced video shows Marjorie Taylor Greene confronting Parkland survivor David Hogg in 2019
After her election, she seized on Trump's false claims that the election was stolen and cheered on his supporters the day before the Capitol was stormed.
"It’s our 1776 moment!" she posted on the conservative friendly social media platform Parler.
Last week, Pelosi pressed for House Republicans to take action against Greene.
"Assigning her to the education committee, when she has mocked the killing of little children" in Newtown, "what could they be thinking, or is thinking too generous a word for what they might be doing?" Pelosi said of Republican leaders. "It’s absolutely appalling."
McCarthy is supposed to meet privately with Greene this week. A spokesperson for the Republican leader declined to comment on Monday.
Although it's not certain he will take action against Greene, McCarthy has punished members of the House Republican caucus before. Former Rep. Steve King, R-Iowa, was stripped of all his committee assignments after expressing support for white supremacists in 2019.
Wasserman Schultz acknowledged Monday that it had long been left up to leaders to remove members of Congress of their own party of their committee assignments. But she said Republicans' reluctance to take action left Democrats with little choice.
"Rep. Greene's appalling behavior both before her election and during her term has helped fuel domestic terrorism, endangered lives of her colleagues and brought shame on the entire House of Representatives," Wasserman Schultz said. "Based on her actions and statements and her belligerent refusal to disavow them, she should not be permitted to participate in the important work of these two influential committees."