Not only is making campaign contributions under a false name not allowed, but the campaign cannot knowingly accept such contributions.
The Federal Election Campaign Act (FECA) directly prohibits any person from making political contributions in the name of another. Title 2 U.S.C. § 441f.
http://a257.g.akamaitech.net/7/257/2422/14mar20010800/edocket.access.gpo.gov/cfr_2003/11cfr110.4.htm
From the FEC website:
http://www.fec.gov/pages/brochures/contrib.shtml#Prohibited_Contributions
Edit: The name on the credit card is not good enough, as a credit card may be in a nickname. My real first name isn't on my credit card. The campaign is reqired to provide your first and last name.
It creates problems for the campaign. They will end up being subtracted from our total today. This is what they have to go through when recieving prohibited contributions:
http://www.fec.gov/pages/brochures/contrib.shtml#Prohibited_Contributions