Within seconds of being asked to denounce white supremacists, President Donald Trump quickly demurred on the question, failing to condemn any group that believes the white race is inherently superior and pointed the blame toward Antifa. 

"Proud Boys – stand back and stand by. But I'll tell you what. I'll tell you what. Somebody's got to do something about Antifa and the left because this is not a right-wing problem," the president said during Tuesday's presidential debate in Cleveland. 

Proud Boys, the far-right all-male group with a history of street violence against left-wing supporters, rejoiced as they viewed the president's response as siding with them.

They shared their excitement on social media and took Trump's statement as marching orders.

"Standing down and standing by sir," the account wrote. The account then posted two videos of the answer, including one with the caption "God. Family. Brotherhood," in which a man howled at the TV in response to Trump's response.

Proud Boys organizer Joe Biggs also posted on Parler, an alternative social media site for conservatives, that he was "standing by," and that the president "basically said to go f--- them up."

"President Trump told the proud boys to stand by because someone needs to deal with ANTIFA ... well sir! we're ready!!" Biggs wrote.

Most recently the group staged a rally in Portland, Oregon, in support of Trump. About 200 people, some armed with guns, attended the rally, short of the expectations of thousands.

Following the president's comments, Democratic nominee Joe Biden defended Antifa, referencing FBI Director Christopher Wray's argument that Antifa was more of a movement or ideology. "Antifa is an idea, not an organization," Biden said.

Trump fired back: "Oh, you got to be kidding."

Biden's response drew a rebuke from former Fox News anchor Megyn Kelly. Kelly was live-tweeting the debate and gawked at Biden’s notion that Antifa is not an organization. 

Soon after the tweet, Kelly was heavily criticized for bashing Biden and awarding Trump the victor of the argument. Kimberley Johnson a HuffPost contributor tweeted out that Kelly "sure acts like a white supremacist." Asha Rangappa, a CNN analyst, also defended Biden and said that he was simply repeating what the FBI director said. 

Antifa, short for "anti-fascist", is a loose affiliation of mostly far-left activists. The movement, which at one point almost entirely disappeared in the U.S., had a surge of interest after the election of Trump.

The group has been prominent during Black Lives Matter protests in many major cities, and have been particularly associated with unrest in Portland, Oregon.

In late August, a self-described anti-fascist, 48-year-old Michael Reinoehl, shot and killed a supporter of Patriot Prayer, a Portland-area group that often marches with the Proud Boys. Reinoehl was shot dead by police the following week.

Following the president's comments, Antifa supporters stormed to social media and were quick to criticize the president over his support for the Proud Boys.

Antifa and the Proud Boys are relatively small and at the most only have a few thousand supporters. But their propensity for violence, particularly when they confront each other on American streets, has made them a much bigger topic of conversation than those numbers suggest.

With speculation arising on if Trump will pledge a peaceful transfer of power to Biden if he loses the election, the stakes are rising on an already contentious election with Trump sending mixed signals to his supporters on how they should respond if the vote doesn’t go their way.

In the aftermath of the debate, White House officials and campaign aides struggled to clean up Trump's comments in which he declined to explicitly condemn white supremacy. 

When asked if Trump wanted to refute or clarify previous responses White House communications director Alyssa Farah said, "I don’t think that there’s anything to clarify.

"He’s told them to stand back. This president has surged federal resources when violent crime warrants it in cities. He’s leading. He doesn’t need any sort of vigilantism," she continued. "That’s never what we’ve called for. What we’ve called for is Democrat mayors and Democrat governors to call up the resources we’re prepared to make available."

Farah was also asked if Trump missed an opportunity to condemn white supremacy, but she defended the president and said that Trump said "sure" when asked if he would he tell white supremacists to "stand down."

"What the president’s referring to there is when we see unrest in our streets and private citizens try to defend themselves or their businesses, that’s a right that they have," Farah added.