Members of Congress have benefited from the lack of bright line IRS rules for the close and intertwining relationships between 501(c)(3) nonprofits and their 501(c)(4) lobbying arms. There is a distinction but not much difference.
Five members of Congress have just returned from a free trip to Israel paid for by the American Israel Education Foundation (AIEF), an IRS Section 501(c)(3) nonprofit. AIEF’s website states it is “affiliated with AIPAC, America’s pro-Israel lobby.” The American Israel Public Affairs Committee is an IRS Section 501(c)(4) organization. AIPAC spent $2,761,388 on lobbying in 2012. Senate and House rules state members may not accept gifts of free travel from a lobbyist or entity that retains or employs registered lobbyists.