[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/01/14/art.portman.gi.jpg caption="Rob Portman is the Republican frontrunner in the Ohio Senate race."](CNN) - Republican Rob Portman, the former congressman and George W. Bush cabinet official now running for Senate in Ohio, finished the latest fundraising period with a big cash advantage over the frontrunner for the Democratic nomination, Lt. Gov. Lee Fisher.
Portman raised $1.3 million in the last three months - more than double the amount of Fisher, who collected $620,000. Also good news for Republicans: Portman has over $5 million on hand, while Fisher has $1.6 million.
Fisher's rival for the Democratic nomination, Ohio Secretary of State Jennifer Brunner, has yet to release her third-quarter numbers, but has admitted raising less than she did in the second quarter, when she took in just $228,000. Some have questioned whether Brunner is planning to drop out of the race, but she has rejected that speculation, telling the Columbus Dispatch Thursday that she has replaced her campaign finance team.
Portman, too, is facing an intra-party challenge - from Cleveland car dealer Thomas Ganley, who has pledged to contribute up to $7 million to fund his campaign.