Sen. John McCain's presidential campaign raised significant funds by renting its list to campaigns for lawmakers such as GOP Rep. Michele Bachmann and GOP Senate candidates Carly Fiorina in California and Joseph DioGuardi in New York.
"Dr. Paul is deeply committed to protecting the privacy of his donors, and has a strict policy against renting his lists," spokesman Jesse Benton said in an email. "Dr. Paul has some of the largest and most valuable lists in the political universe, and receives regular offers to sell or rent them for hundreds of thousands of dollars. He has only rented his list to his son, Senator Paul."
While purchasing lists of campaign donors is common, some lawmakers are choosing to stay out of the fray of this lucrative process.
"I know a fair number of candidates who don't rent out their lists," Burns said, "because they don't want their donors tapped into and otherwise cannibalized by other political campaigns."