Lobbyists are paid big bucks to convince members of Congress to vote a certain way. They do this through meetings in which they lay out their point of view. They also sometimes provide members of Congress with expensive meals, golf trips and campaign contributions to ensure access.

In addition to the direct contributions detailed below, the “bundling” of contributions from individuals by lobbyists substantially enabled the rapid increase in political expenditures in recent years, which are not reflected in the chart. This chart is only the tip of the iceberg in documenting lobbyists’ influence through fundraising.

Members of Congress are elected to represent constituents, yet many candidates for office receive contributions from people who do not live in their states or districts. Large amounts of out-of-state contributors may indicate that candidates are gearing up for a national election, that they are beholden to special interests located outside their state or district, or both.

When candidates are collecting dollars, it is easier to go to a relatively small number of wealthy donors who can write $2,000 checks than to gather many, many more small contributions from a large number of people. Candidates with many small donations likely reached out to a more economically and socially diverse group of citizens.

Federal election law does not require itemized reporting of donations of $200 or less. Members of Congress who receive more money from small donors, especially in proportion to their overall contributions, probably are turning more to their whole constituencies to raise money instead of to a few well-heeled supporters.

Members of Congress are elected to represent constituents, but often receive contributions from special interest organizations known as political action committees (PACs). PACs may give up to $5,000 per candidate per election and typically target elections in which their donations will have the biggest impact.

Some members included in our overall charts have stated publicly in news reports or other sources that they do not accept any PAC money whatsoever. PACs, which are the source for the data below, do not always report returned donations. The following members have indicated that they take no money from PACs: Senators Maria Cantwell (D.-Wash.), Herb Kohl (D.-Wisc.) and Mark Dayton (D.-Minn); as well as Rep.’s Hostettler (D-Mass.), Inglis (R-S.C.), Meehan (D-Mass.), Leach (R-Iowa), Osborne (R-Neb.) and Platts (R-Pa.).