Illinois Sen. Mark S. Kirk is the only Republican to rescind his endorsement of his party's presidential nominee Donald Trump, and Trump hasn't forgotten about it.
Trump told a town hall meeting in New Hampshire on Thursday that Kirk was "not doing so well" but that it was "not his problem."
Unsurprisingly, the Illinois Democratic Party agreed with the real estate mogul.
"Donald Trump has proven himself totally unfit to be president, but even a broken clock is right twice a day," said Sean Savett, a party spokesman.
Kirk's campaign, meanwhile, released an internal poll showing the senator "within striking distance" of his opponent, Democratic Rep. Tammy Duckworth. The two-term congresswoman led 41 to 37 percent, within the poll's 4-point margin of error.
The polling memo stated that "Duckworth continues to underperform the top of the ticket (Democratic presidential candidate Hillary Clinton)," while "Kirk is outperforming Trump by a net of 13 points."
"Further demonstration that the race is tight is that the [National Republican Senatorial Committee] is currently up on air in Chicago, Rockford, Springfield and Peoria media markets," Kirk campaign spokeswoman Eleni Demertzis said.
The most recent nonpartisan poll in the state gave Duckworth a double-digit lead. A Southern Illinois University Carbondale poll released Tuesday showed the congresswoman ahead, 48 percent to 34 percent.
Earlier polls had also shown Duckworth in the lead, though by smaller margins.