Obama contributes to campaign fund he didn't use

President Barack Obama didn't accept public money in the 2008 election but that didn't stop him from checking the election funding box on his federal income tax return. 

The Obamas and Vice President and his wife Jill contributed a total of $12 to the Presidential Election Campaign Fund, a pool of public money available to eligible candidates running for president. 

In 2008, Obama became the first major candidate to decline matching public funds for the primary or the general election, leading to the lowest amount of spending since 1984. Candidates spent about $139 million two years ago, compared with $207 million in 2004 and $239 million in 2000, the most ever spent by presidential candidates, according to the Federal Election Commission, which oversees the program and determines eligibility. 

Republican nominee John McCain declined money for the 2008 primaries but accepted $84.1 million for the general election. 

Overall, Democratic primary candidates spent $2.6 million in 2008 while Republicans used $17.5 million of the fund. Each party received about $17 million for their conventions. 

Before 2008, the previous spending low was $133 million and has ranged from $73 million when the fund was established in 1976 to the high in 2000. The amount was increased from $1 to $3 in 1994. 

Public participation has declined from a high of 28.7 percent in 1980 to a low of 8.3 percent in 2007, according to the latest figures from the FEC. 

Candidates become eligible for funds once they have raised $5,000 in 20 states. Only contributions from individuals are matchable and only $250 of each person's campaign contribution can be applied toward the $5,000 threshold in each state. Only $250 of that contribution is ever matchable, according to the FEC.