Joe Walsh, a former Republican congressman who launched a primary challenge against President Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE, on Monday addressed past controversial remarks, saying that he wasn’t a racist but had said "racist things."

"I wouldn’t call myself a racist, but I would say, John, I’ve said racist things on Twitter. There's no doubt about it. And an apology is not enough," Walsh, who represented Illinois's 8th Congressional District between 2011 and 2013, said on MSNBC.

ADVERTISEMENT

Walsh's comments came after he was confronted by MSNBC's John Heilemann about his history of controversial statements, including the accusation that former President Obama was a Muslim.

"You’ve apologized for helping to spawn Trump. You’ve apologized for going too far," Heilemann said. "For a lot of people, the fact is the president is a stone-cold racist and so are you."

"You can apologize for various things. Apologizing for burping at the table or using the wrong fork with your main course is different from offering some kind of a genuine recognition that not just 'I said things that are offensive' but that 'I’m a racist. I said racist stuff,'" Heilemann added.

Walsh responded by saying he's sent tweets he regrets.

"When I said Barack Obama Barack Hussein ObamaDemocrats ramp up pressure on Lieberman to drop out of Georgia Senate race The Hill's Campaign Report: Biden on Trump: 'He'll leave' l GOP laywers brush off Trump's election remarks l Obama's endorsements Trump pledges to make Juneteenth a federal holiday, designate KKK a terrorist group in pitch to Black voters MORE was a Muslim, that was a horrible thing to say, and I said it because I was so disgusted with Obama’s policy toward Israel that I went a bad, ugly step," he said.

"I’ve probably sent out 40,000 tweets in the last six years. No excuse. You and I could sit down and find 200 to 300 that you’d say, 'Walsh, what were you thinking?' And all I can do is own them and explain them and apologize as sincerely as I can for the ones that deserve an apology," Walsh added.

Walsh, who has been openly critical of Trump's presidency, on Sunday announced that he was launching a primary challenge against the president.

"I'm running because he's unfit. Somebody needs to step up, and there needs to be an alternative," Walsh said on ABC's "This Week." "The country is sick of this guy's tantrum. He's a child. Again, the litany. He lies every time he opens his mouth. Look at what's happened this week. The president of the United States is tweeting us into a recession."

Many of Walsh's most inflammatory remarks have received new attention since Sunday, including tweeting on several occasions the conspiracy theory that Obama is a Muslim.

“Obama is a Muslim. Happy New Year!” Walsh tweeted in January 2017.

He's since expressed remorse for the comments, saying in August that he continues "to apologize for having ever said that." But he suggested that Obama's policy toward Israel had caused him to make the remark, tweeting, "I don’t believe [Obama] was Israel’s friend."

The former lawmaker has also drawn scrutiny for his remarks about Islam and race as well as his criticism of African American protestors. In 2016, he blamed a police shooting on organizers of the Black Lives Matter movement, who had condemned the killings.