The $4.5 million the former U.S. senator from Pennsylvania raised in January was more than twice the total he raised in 2011, USA Today reported Tuesday.
Financial disclosure forms filed with the Federal Election Commission also indicate former House Speaker Newt Gingrich raised nearly $5.6 million in January, but he had nearly as much debt as available cash by month's end.
U.S. Rep. Ron Paul of Texas said he collected $4.5 million in January, while a super political action group supporting his campaign reported raising nearly $2.4 million.
Meanwhile former Massachusetts Gov. Mitt Romney's fundraising fell to $6.5 million in January as he fends off challenges from his GOP competitors, his campaign said Monday.
Overall, Romney has collected $64 million for his second presidential bid but trails behind the $151 million raised by President Obama to date, USA Today said. Romney ended January with about $7.7 million cash in the bank.
"We are the only campaign who has the organization and resources to go the distance of a long primary process," Romney finance chairman Spencer Zwick said in a statement. "We know there is a long road ahead, and we will remain steady."
Pro-Romney super-PAC Restore Our Future ended January with $16.3 million in the bank after spending nearly $14 million.
Winning Our Future, a super-PAC aligned with Gingrich, raised $11 million in January, of which $10 million came from casino entrepreneur Sheldon Adelson and his wife, USA Today said. The super-PAC ended the month with $2.4 million in the bank.