Obviously Republicans rely on big donors to drive their campaigns... You know it's worse when the senators have to create a Political Action Committee solely for getting around more donation laws.  

Top political action committees and top lobbyists have been writing bigger than normal checks to benefit the campaigns of various Republican Senators who have formed a joint fundraising committee, the 2007 Senator's Classic Committee. Some PACs have written checks for $23,000 and a top Washington lobbyist has a written check for $9,600.

In June the committee gave funds to various candidates; Alexander $21,000; Chambliss $16,500; Cochran $24,000; Coleman $19,000; Collins $18,000; Craig $23,000; Dole $15,000; Enzi $30,000; Inhofe $18,000; Sessions $23,000; Gordon Smith $14,500; Graham $19,000; McConnell $23,000; Roberts $28,000; Domenici $16,000; Warner $39,000; Stevens $16,000; Sununu $14,500; and Cornyn $25,000.

As you can see, warner recieved almost 40,000$ out of his 71,000$ from this PAC created to gather Lobbyist and Corporate PAC's together to protect Republicans.  The PAC also shows it donated to 19 of 22 senators going up for re-election in 2008.  

"PACs and Lobbyists Write Bigger Than Normal Checks"
http://www.politicalmoneyline.com/ -  You have to scroll down and look for the article title.