© Getty Images
Rep. Tammy Duckworth (D-Ill.) outraised Illinois Sen. Mark KirkMark KirkLeaked ObamaCare bill would defund Planned Parenthood GOP senator won't vote to defund Planned Parenthood The Hill's 12:30 Report MORE (R) by almost $600,000 in the fourth quarter of 2015, as the two gear up for what could be one of the tightest elections of 2016.
Duckworth brought in $1.6 million in the quarter, which bumps up her cash on hand to $3.65 million.
Kirk raised $1 million in the quarter, ending 2015 with $3.8 million on hand.
Both campaigns self-reported the fundraising totals ahead of the Jan. 31 deadline, so further details won't be available until after that deadline.
Duckworth ended the third quarter with about $2.85 million in her bank account, compared to Kirk's $3.63 million. She all but closed that gap to end the year, suggesting a more effective quarter of fundraising by the challenger.
Kirk's fourth-quarter haul ranks lower than other vulnerable GOP Senate incumbents who have reported donations in the fourth quarter.
Sen. Rob Portman (R-Ohio) and Sen. Kelly Ayotte (R-N.H.) both raised more than $2 million over the same span ahead of similarly difficult reelection bids.
Kevin Artl, Kirk's campaign manager, noted in a statement to The Hill that Kirk "has raised over $8 million from thousands of donors across Illinois in preparation for his re-election campaign."
He added that the senator plans to "continue to take his message of making America safer and stronger directly to the people of Illinois."
Kaitlin Fahey, Duckworth's campaign manager, bashed Kirk as funded by "Wall Street and corporate special interests" in its campaign fundraising statement.
“Tammy continues to articulate a vision for a state and country that looks after its people and grows from the middle out rather than the top down, and it’s clearly resonating,” she said.
Duckworth, the Democratic establishment's favorite in the primary, has won the backing of the Democratic Senatorial Campaign Committee as well as endorsements from many Illinois lawmakers including Sen. Dick Durbin.
Democratic rival Andrea Zopp, a former Chicago nonprofit head and public prosecutor, is backed by Rep. Danny Davis and former Obama chief of staff Bill Daley.
Napoleon Harris, a state senator and former NFL linebacker, is also running in the Democratic primary.
No top-tier primary challenger to Kirk ever materialized, but he is running against businessman James Marter, who is challenging him from the right.
- Updated at 3:32 p.m.