From Bush's site:
https://www.donationreport.com/init/controller/ProcessEntryCmd?key=I5B7P3F2B6
"The Bush-Cheney '04 Compliance Committee needs your support to ensure compliance with federal law for general election legal and accounting services. Will you make your contribution today?"
Both Bush and Kerry are accepting $75 million federal funds. So they can't use anything other than government money once they had had their conventions. Any money you donate to either candidate goes to their legal fund, which they use it as stated above.
You don't have to donate to GOP. There are 527s like Swift Vets, Club for Growth, etc.
I will donate money to Bush ... never the party.