Paul Ryan, R-Wis., the speaker of the House of Representatives, transferred $2 million to the National Republican Congressional Committee in August, according to Politico.
That fundraising total puts Ryan's contributions to the House Republican campaign group at almost $30 million for 2017, the report said.
Ryan's total also was more than half of what the NRCC raised in the month of August.
The quick pace of the NRCC's fundraising will be a benefit as the Republicans look toward 2018 midterm elections, after a number of Republican congressmen have announced that they would be retiring. Races to fill those seats will be more competitive without incumbents to defend them, the Politico report said.
"Each retirement costs a couple million dollars of campaign money, and Republicans have over-performed in recent years, so we have some vulnerabilities," said Tom Davis, former NRCC chairman.
"Any criticism Ryan gets, he's a fundraising champ. It's hard to think of anyone who has the persona that can raise money the way he's done," Davis added.
As of July, the Democrats' congressional campaign committee had brought in more than the NRCC for the third month in a row, according to the Washington Examiner.
However, they still had less money at the end of July than the Republicans, the Politico report said.
A national Republican strategist said having cash on hand does not guarantee a win. "A cash on hand advantage is always good, but in a bad year, you can outspend your opponent and still lose," the strategist said in Politico.