After months of fighting to separate himself from Republican nominee Donald Trump, whose inflammatory rhetoric has alienated moderate voters in his more moderate state, Illinois Sen. Mark Kirk stumbled into the kind of racially-charged, controversial territory he spent months speaking out against.
On Thursday night, the white male Republican senator questioned the American military lineage of the war veteran, minority woman running against him. When Rep. Tammy Duckworth, who lost both her legs fighting in Iraq, mentioned that her family's military service traces back to the Revolutionary War, Kirk leaned into the microphone and replied "I had forgotten that your parents came all the way from Thailand to serve George Washington."
For the Republican senator polling an average of 7 points below Duckworth, the remark has the potential to be the nail in the coffin, undoing months of Kirk's efforts to distance himself from Trump and tying his bid even closer to the controversial nominee with just days to go before the nation votes.
Condemnation arrived swiftly, with Democratic nominee Hillary Clinton tweeting "it's not really that hard to grasp" and Duckworth responding with a telling family photo spelling out her family's heritage.
Kirk apologized by lunchtime on Friday, but long after his comments gained national attention on social media and cable news.
As a Republican seeking reelection, Kirk's political fortunes have been complicated by his party's presidential nominee, whose rise was rooted in racially charged assumptions about Mexican immigrants and the birthplace of the president.
While this isn't Kirk's first controversy in recent years — he called the unmarried Republican Sen. Lindsey Graham a "bro with no ho" and critically referred to President Barack Obama as the "drug dealer in chief" for his handling of Iran — the senator has worked hard to distance his campaign from Trump.
After endorsing him early on, Kirk became the first Republican senator to un-endorse Trump back in June amid the nominee's early headline-dominating controversies. Kirk later called him "too bigoted and racist" to be president and ran ads against his party's nominee, saying in Spanish "I do not support Trump" in short television spots airing on Telemundo and Hispanic this fall.
Running in a blue state, Kirk had little choice: the state hasn't gone red in a presidential election since 1988 and in the few polls conducted in the state Clinton is polling in double digits ahead of Trump.
The embattled senator championed his own tough recovery from a stroke that nearly killed him as a learning experience and sought to differentiate himself as more moderate than his controversial national nominee, arguing instead that Trump's candidacy helped him remind his blue state of his independent streak, and votes for gun restrictions and support of gay rights.
As his electoral hopes and Trump's numbers dropped throughout the summer and fall, Kirk was one of the most outspoken Republicans insisting that Trump should be pulled from the ballot, despite the fact that voting had already begun and there was no way to remove him.
In the end, Kirk will end his bid just as he began it: Tied to Trump.