An Illinois GOP senator sniped at his Democratic opponent's heritage during a debate

Republican Sen. Mark Kirk sniped at his Democratic challenger Tammy Duckworth by questioning her family's heritage.

Duckworth was sharing a story about her family's military service record during an Illinois debate Thursday night.

"My family has served this nation in uniform going back to the Revolution. I am a daughter of the American Revolution," Duckworth said. "I've bled for this nation. But I still want to be there in the Senate when the drums of war sound. Because people are quick to sound the drums of war, and I want to be there to say this is what it costs, this is what you're asking us to do."

"And if that's the case, I'll go. It's the families like mine that bleed first," Duckworth continued. "But let's make sure that the American people understand what we are engaging in and let's hold our allies accountable because we can't do it all."

Kirk rebutted, "I'd forgotten that your parents came all the way from Thailand to serve George Washington."

Awkward silence followed his rebuttal - Duckworth didn't respond to Kirk - and the moderator moved onto the next question.

The Democratic Senatorial Campaign Committee quickly bashed Kirk for his comments, saying his attack on Duckworth's family was "offensive, wrong and racist."

Duckworth's mother is Thai, but her family on her father's side has roots in America. 

Watch the exchange blow: