CHICAGO _ Sen. Mark Kirk apologized to Rep. Tammy Duckworth on Friday for a comment he made about her family's ancestry and military background during a debate in the Illinois Senate race on Thursday night.
"Sincere apologies to an American hero, Tammy Duckworth, and gratitude for her family's service," Kirk posted on his official campaign Twitter account.
The apology came less than 24 hours after the first-term Republican created a social media firestorm over his remark to the two-term Democratic congresswoman, who is challenging him for his Senate seat.
At one point during the 90-minute debate at the University of Illinois at Springfield, Duckworth talked about her family's long history of involvement in the U.S. military, describing herself as a "daughter of the American Revolution" who has "bled for this nation."
When it was Kirk's turn to offer a rebuttal, he offered a single sentence: "I had forgotten that your parents came all the way from Thailand to serve George Washington."
There was an awkward pause, and the comment left some in the audience with a look of puzzlement.
Duckworth, who was born in Bangkok, Thailand, to a mother of Chinese heritage and a father of British descent, replied: "There's been members of my family serving on my father's side since the American Revolution." She said she was "proud of both my father's side and my mother's side as an immigrant."
Kirk's comment drew quick national attention. The left-wing publication Mother Jones called it a "bizarre and offensive quip."
Kellyanne Conway, campaign manager for Republican presidential candidate Donald Trump, took to Twitter for some payback against Kirk, who unendorsed Trump this year and has called the former reality show star unfit to be president.
"The same Mark Kirk that unendorsed his party's presidential nominee and called him out in paid ads? Gotcha. Good luck," Conway posted on Twitter over an online publication's tweeted headline "Senator Mark Kirk mocks disabled Iraq war vet Tammy Duckworth in debate for her mixed-race heritage."
During the debate, Kirk pointedly said he had unendorsed Trump because of the Republican nominee's criticism of the Mexican heritage of a federal judge from Indiana who was overseeing a trial involving Trump University.
Duckworth's campaign quickly sent out a campaign fundraising solicitation off Kirk's comment, calling it "outrageous" and "appalling." Her campaign put out a lengthy list of headlines highlighting the attack, and updated it on Friday morning.
Kirk, who is recovering from a major stroke suffered in late January 2012, made a series of controversial statements last year. The one that garnered much attention was his live mic reference during a Senate committee hearing of bachelor colleague Sen. Lindsey Graham of South Carolina as a "bro with no ho."
Following the controversial statements, some top Illinois Republicans were privately fretting about Kirk's re-election bid in July 2015, but the GOP stuck by him. At the time, the Chicago Tribune reported, officials with the National Republican Senatorial Committee suggested that Kirk stay out of the media.
Kirk's campaign largely heeded that message, and even employed a low-risk strategy in the first debate. But on Thursday night, Kirk opened the throttle, and out came the remark about Duckworth's heritage.
Duckworth served in the Iraq War and lost her legs after the helicopter she co-piloted was felled by a rocket-propelled grenade. Kirk served as an intelligence officer in the Naval Reserve.
