Senator Pat Roberts raised about $850,000 for his re-election in the last three months to keep a wide lead over his Democratic rival in the money race.
The Kansas Republican now has about $3.1 million in the bank to spend on his campaign against former Democratic Rep. Jim Slattery.
Slattery raised nearly $500,000 over the same period. That's less than the $650,000 that Roberts spent during the latest quarter, with most of that on television ads.
Slattery's campaign does not yet have cash on hand figures, but a spokeswoman says he has not spent much money since entering the race in March.
Roberts has had ads around the state for more than two weeks.