I would like to learn the following about contributions to federal
candidates (candidates for U.S. Congress, U.S. Senate and the
President), for a given election cycle (say, 2003-2004):

1. How many organizational (non-individual) entities contribute to
Federal candidates, subdivided by type? (How many PACs, how many party
committees, etc).

2. If we sorted all the entities in (1) in order of total giving,
starting from the biggest contributors, how many entities would be
needed to make up 50% of total contributions? 80% of total
contributions? I assume that it takes much less than 50% of the top
PACs to make up 50% of the contributions.

Thank you.