According to Federal Election Commission filings released by the Coleman and Franken campaigns, Coleman ended September with nearly $4 million in campaign cash, compared to Franken's more than $2.75 million.
As of Sept. 30, Coleman also led Franken in total fundraising, with nearly $18 million compared to Franken's more than $16 million.
An MPR News analysis found between them, Coleman and Franken have contracts to spend more than $8 million on television ads in the Twin Cities alone.
Carleton College political science professor Steven Schier says with the kind of money available to the two candidates, many more ads will come.
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"I've been seeing ads, unrelenting ads about the Senate race. And ... I'm in for another several weeks of this."
"I've been seeing ads, unrelenting ads about the Senate race. And what these fundraising numbers tell me is that I'm in for another several weeks of this," said Schier.
Schier and other political analysts say because Coleman and Franken are so well funded, they've been able to produce an unusually large number of TV ads. Some of the highly customized spots play out like dialogues, with one campaign responding to the other.
Schier says Coleman's lead in overall fundraising is a testament to the strength of his campaign. Schier says he's not surprised that Coleman fell behind Franken in the latest reporting period, given the tough environment Republicans face.
"The demand for money by Republican candidates outstrips the supply of money available to them this fall," said Schier. "And I think it reflects the decline, or the shortfall in Coleman's fundraising numbers."
Schier says that tough environment for the GOP has helped Franken well beyond fundraising. Scheir says the financial crisis has shifted attention away from Franken's past as an entertainer.
"I think Norm Coleman needs more cash on hand at present because he's facing a very difficult environment. The financial crisis of recent weeks has hurt most Republican incumbents, and I think it's hurt Norm Coleman," said Schier. "He's going to have to fight very hard to hold on to his Senate seat, and he's going to need all the extra money he can find."
Independence Party Senate candidate Dean Barkley said he hoped to raise as much as $500,000 -- almost nothing compared to the kind of money the other two major party candidates have brought to the race.
Barkley appears to be having a difficult time meeting his goal. So far, Barkley's campaign says he's raised about $75,000, and ended September with about $5,000 in cash.
Candidates in the state's congressional races also reported their fundraising numbers.
In the 2nd Congressional District, GOP Rep. John Kline raised $145,000, compared to $103,000 for Democratic challenger Steve Sarvi. Kline had $675,000 on hand, compared to $136,000 for Sarvi.
In the 3rd Congressional District, Republican Erik Paulsen raised $523,830, and had $1.1 million in the bank. Democrat Ashwin Madia raised $645,470, and had $995,000 in the bank.
In the 1st Congressional District, Democratic Rep. Tim Walz reported raising $225,000 during the period, and finishing with $1.1 million, while Republican challenger Brian Davis raised $116,000 and had $317,000 in cash.
And in the 6th Congressional District, Republican Rep. Michele Bachmann raised $222,000 and finished with $1.4 million, while Democratic rival Elwyn Tinklenberg raised $313,000 and had $356,000 in the bank.
(The Associated Press contributed to this report)