Presidential Funding Act of 2010

Presidential Funding Act of 2010 - Amends the Internal Revenue Code, with respect to public financing of presidential election campaigns, to: (1) quadruple (from 1:1 to 4:1) the matching rate for contributions to primary election candidates or their authorized committees for contributions not exceeding $200 (currently, $250); (2) eliminate primary and general election spending limits on participating candidates; (3) increase the eligibility threshold for receiving matching payments from $5,000 to $25,000 in contributions from residents of each of at least 20 states; (4) limit the maximum campaign contribution by individuals to $1,000 for primaries (currently, $2,400); (5) allow an inflation adjustment for periods after 2012 for contribution limitations and matching payment amounts; (6) prohibit contributions raised by lobbyists or political action committees from qualifying for matching fund payments; (7) require candidates who accept public financing in primary elections to accept such financing in general elections; (8) change the starting date for payment of matching funds to primary candidates from January 1 of the election year to 6 months before the first presidential primary or caucus; (9) allow an equal payment to eligible candidates in a presidential election of $50 million with additional matching funds according to a specified formula; and (10) increase from $3 to $10 ($6 to $20 for joint returns) the tax checkoff for the Presidential Election Campaign Fund.

Amends the Federal Election Campaign Act of 1971 to: (1) increase to $50 million the limit on coordinated spending by a national party and its presidential candidate; (2) prohibit political parties from spending unregulated funds (soft money) on their national conventions; (3) prohibit an authorized committee of a candidate from establishing a joint fundraising committee with a political committee other than the candidate's authorized committee; and (4) require presidential campaign committees to disclose information about bundled campaign contributions (i.e., a series of contributions exceeding specified threshold amounts).

Amends the Reclamation Reform Act of 1982 to offset the cost of this Act by modifying irrigation subsidies for specified single farm operations.