Every year you are asked by your tax preparer (or your software) if you want to donate $3 of your federal tax to the Presidential Election Campaign Fund. Do you know where this $3 comes from or where it goes?
If you select YES, $3 of your total federal tax liability is diverted from the U.S. Treasury to the campaign fund for qualified presidential candidates - most of this goes to the primary candidates of the Republican and Democratic parties. It was created to reduce dependence upon contributions from private parties. They can then spend the dollars on campaign advertising, travel, or for their staff.
While checking the YES box does not increase your personal tax, it does reduce the amount of receipts of the federal government - which may increase your tax in the future. You can learn more at http://ow.ly/tu99c