A committee formed by business, labor, or other special-interest groups to raise money and make contributions to the campaigns of political candidates whom they support. PAC an organization formed by a business, union, or interest group to help raise money for politicians who support their ideas. In U.S. politics, an organization whose purpose is to raise and distribute campaign funds to candidates seeking political office. PACs rose to prominence after the Federal Election Campaign Act (1971) limited the amount of money any corporation, union, or private individual could give to a candidate. PACs were able to circumvent these limits by soliciting smaller contributions from a much larger number of individuals. During the late 20th and early 21st centuries the vast amounts of money raised by PACs greatly increased the cost of running for office and led to efforts to reform this method of financing campaigns