Taken from July 2004 Proliteracy newsletter:
"... This month, we want to alert you to a new warning issued by the IRS about voter education. Not-for-profit organizations classified as 501(c)3 are prohibited from participating or intervening in any political campaign on behalf of, or in opposition to, any candidate for public office. Prohibited activities may include simply thanking a candidate publicly for his or her support of your program during an election campaign. Penalties for engaging in prohibited campaign activities can include the possible loss or reclassification of your 501(c)3 status.
You must be very careful about endorsing, or appearing to endorse, any candidate for office during an election campaign. However, this does not preclude you from educating political candidates in your community about your program, or even for asking them to articulate their literacy positions and sharing those positions with literacy stakeholders in your community. Be sure that you let your stakeholders form their own conclusions, however. And be sure to thank them publicly for their support as much as possible when the election is over!"