Joe Biden (D). (Getty Images)

Ilona Schumicky and Liam Sigler contributed to this story.

(CNSNews.com) – Despite the well-documented violence of the radical left Antifa group -- the Department of Homeland Security classifies it as “domestic terrorist violence” – not one of the 23 Democrats running for president would condemn Antifa when repeatedly asked by CNSNews.com over the course of 12 business days.

The Trump administration did respond, within a day, condemning Antifa.

In emails and telephone calls to the press offices and campaigns of the 23 Democrats running and to the Trump campaign, CNSNews.com asked the candidates to answer two questions about Antifa based on background about the group reported by Politico.

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On Sept. 1, 2017, Politico ran a story entitled, “FBI, Homeland Security warn of more ‘antifa’ attacks.”

Politico reported, “Federal authorities have been warning state and local officials since early 2016 that leftist extremists known as ‘antifa’ had become increasingly confrontational and dangerous, so much so that the Department of Homeland Security formally classified their activities as ‘domestic terrorist violence,’ according to interviews and confidential law enforcement documents obtained by POLITICO.”

Politico went on to quote a senior law enforcement official:

“‘It was in that period [as the Trump campaign emerged] that we really became aware of them,’ said one senior law enforcement official tracking domestic extremists in a state that has become a front line for clashes between the groups. ‘These antifa guys were showing up with weapons, shields and bike helmets and just beating the shit out of people. … They’re using Molotov cocktails, they’re starting fires, they’re throwing bombs and smashing windows.’”

CNSNews.com then asked the candidates, 1) Do you condemn Antifa? And 2) Do you believe federal law enforcement agencies should take all lawful steps necessary to prevent Antifa from engaging in ‘domestic terrorist violence’ during the 2020 U.S. election campaign?

Sen. Cory Booker (D-N.J.) (Getty Images)

CNSNews.com repeatedly sent these questions to the 24 candidates by email and telephone between July 23 and Aug. 7. Not one Democratic candidate responded. (The Trump campaign answered on July 24.)

Many of the Democratic candidates’ press offices confirmed they had received the question and thanked CNSNews.com for “reaching out.”

For instance, the Beto 2020 campaign said, “Thanks for reaching out again. We have passed your follow-up request along to the Press Team.” The Hickenlooper 2020 campaign said, “Thank you for reaching out! I’ve passed along your information to our press team, and they should be in touch soon…. Thanks and giddy up!”

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Although the Democrats did not condemn Antifa, the Donald Trump for President campaign did. Kayleigh McEnany, national press secretary for the campaign, told CNSNews.com in an email:

"The Trump campaign condemns all forms of violence. Meanwhile, Democrats in Congress refuse to condemn Antifa's violent attacks against innocent Americans. From beating an innocent journalist to the point of having a brain hemorrhage to firebombing an ICE facility, Antifa has committed a variety of violent attacks with one common response from Democrats: silence."

Photojournalist Andy Ngo, who was assaulted and beaten by Antifa. (Getty Images)

In addition to the Trump campaign, CNSNews.com repeatedly contacted the press offices of the following Democratic candidates over the course of 12 working days, but not one responded:

Michael Bennet

Joe Biden

Bill deBlasio

Cory Booker

Steven Bullock

Pete Buttigieg

Julian Castro

John Delaney

Tulsi Gabbard

Kirsten Gillibrand

Andrew Yang

Kamala Harris

John Hickenlooper

Jay Inslee

Amy Klobuchar

Wayne Messam

Marianne Williamson

Seth Moulton

Francis "Beto" O'Rourke

Tim Ryan

Bernie Sanders

Tom Steyer

Elizabeth Warren