Chants of “send her back” by supporters of President Donald Trump, attacking Somali-born U.S. Representative Ilhan Omar, triggered a wave of concern among congressional Republicans on Thursday, while Omar said Trump was “spewing fascist ideology.”

Alarmed that the inflammatory chant might become a theme of the 2020 election campaign, Republican leaders in the US House of Representatives discussed the potential political risks at a breakfast with Vice President Mike Pence, according to Representative Mark Walker of North Carolina.

“We cannot be defined by this,” said Walker, telling reporters that he raised the topic at the Pence breakfast.

“That does not need to be our campaign call.”

“We want our policies from the House, all the way up to the administration, to define us. And we feel like we can win on that,” added Walker, a conservative.

Walker and other Republicans denounced the language used by Trump's supporters, which played off of a Twitter attack launched by Trump over the weekend in which he said Omar and three other Democratic lawmakers, all minority women, should “go back” where they came from.

All four of them are US citizens and, with the exception of Omar, were born in the United States.

The House Republicans stopped short of blaming the president and Trump at midday tried to distance himself from the chant.

“I felt a little bit badly about it,” Trump told reporters at the White House. “I would say that I was not happy with it. I disagreed with it. But again I didn't say that. They did. And I disagreed with,” the president said.

Omar blamed the president: “As much as he's spewing his fascist ideology on stage, telling US citizens to go back because they don't agree with his detrimental policies for our country, we tell people that here in the United States, dissent is patriotic.”

The other three progressive lawmakers targeted by Trump in his tweets and subsequent statements are US Representatives Alexandria Ocasio-Cortez, Rashida Tlaib and Ayanna Pressley.

The Democratic-controlled House voted on Tuesday to condemn Trump's tweets as racist.

At the rally, Trump intensified his vilification of the four and underscored that such attacks will be a key part of his strategy for winning re-election in 2020.

He went on a 20-minute diatribe about them, saying they were welcome to leave the country if they do not like his policies on issues such as immigration and defending Israel.

US Representative Justin Amash, a longtime Trump critic who left the Republican Party this month to become an independent, tweeted, “A chant like 'Send her back!' is ugly and dangerous, and it is the inevitable consequence of President Trumps demagoguery. This is how history's worst episodes begin. We must not allow this man to take us to such a place.” The outrage capped a tumultuous Trump-dominated week that took its toll on House members.

On Wednesday, the House voted to kill for now a resolution brought by Democratic Representative Al Green that called for Trump's impeachment. Ninety-five Democrats voted against setting the measure aside in a sign of increased party division.

“We've got to take a deep breath. We all need to get out of here,” Democratic Representative Debbie Dingell told reporters.

“Nerves are frayed. People are on edge. The Republican caucus is at each others throats. Were at each others throats. We need to all go home ... and listen to what our constituents care about,” she said.