The American Civil Liberties Union today filed a federal lawsuit challenging a South Dakota law that moved the deadline for new political parties striving for a place on the 2016 ballot.The lawsuit, filed on behalf of South Dakota's Libertarian Party and Constitution Party, challenges a section of the law that shifted the deadline for new parties to submit declarations to participate in primary elections backward by four weeks from the last Tuesday in March prior to the date of the primary election to the first Tuesday in March. The plaintiffs are asking the deadline be set for no earlier than March 29 for a party that wants to participate in South Dakotas primary election, and August 1 for a party that does not need to participate in a primary election.