felonvoting.procon.org: State Felon Voting Laws(Current as of Apr. 08, 2010)
ACLU: Voting Rights for People with Criminal Records: 2008 State Legislative and Policy Changes (This is from 2008 and may have changed)
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examples:
superiortelegram.com: Felons can vote in Wisconsin after they have completed their probation or parole.
media.www.oxyweekly.com:This January, in the landmark case Farrakhan vs. Gregoire, the Ninth Circuit Court of Appeals in San Francisco overturned a Washington state law that prohibits convicted felons from voting until they have finished their probation and parole. In this decision, the court ruled that it was unconstitutional for Washington state to disenfranchise felons, because a disproportionate percentage of minorities are prosecuted and convicted of felonies. Therefore, according to the court, the disenfranchisement ordinance violated the right to vote regardless of race outlined in the Fifteenth Amendment.
prospect.org: Ex-felons are routinely disenfranchised due to confusion over state laws. Now, Congress is considering a bill that would restore voting rights to prisoners as soon as they pay their debt to society.