The campaign arm of House Democrats extended its fundraising advantage over Republicans in September, when the two parties clashed over a partial government shutdown that began as the third quarter ended.
The Democratic Congressional Campaign Committee raised $8.4 million last month compared with $5.3 million for the National Republican Congressional Committee, according to reports filed with the Federal Election Commission over the weekend.
The $3.1 million gap is the biggest for either House campaign committee in any month this year, according to data compiled by Political Capital.
The DCCC raised $58.2 million in the first nine months of this year, up 21 percent from $47.9 million over a similar period in 2011. It began October with $21.6 million in the bank, more than twice the $9.5 million it had on hand two years ago.
The DCCC received $181,000 last month from the campaign committee of House Minority Leader Nancy Pelosi of California and $100,000 each from the campaigns of Minority Whip Steny Hoyer of Maryland and James Clyburn of South Carolina, the third-ranking House Democrat.
The DCCC received the maximum $32,400 individual donation from Chellie Pingree of Maine; Tim Zagat, the president of Zagat Survey LLC; and Derek E. Kaufman, the head of global fixed income for Citadel LLC.
The NRCC received $1.2 million from two committees linked to Speaker John Boehner of Ohio.
The NRCC received a $32,400 donation from Charles G. Koch, the chairman and chief executive officer of Koch Industries Inc. Koch is the sixth-richest person in the world, with a net worth of $46.5 billion, according to the Bloomberg Billionaires Index.
Former Rep. Connie Mack IV of Florida, who served from 2005 to 2013 and lost a Senate race in 2012, donated $32,400 to the NRCC.
Republicans hold a 231-200 majority in the House, where there are four vacancies, including three in districts that Republicans are defending. Democrats need a net gain of 17 seats to win a majority.