Libertarian presidential candidate Bob Barr has filed a lawsuit in Texas arguing that Republican nominee John McCain and Democratic nominee Barack Obama missed the deadline to get on the state’s November ballot.

The United States does not hold a national election: Each state sets the rules for how candidates can get their names on the ballot. In Texas, each candidate must provide written certification of his or her nomination on the 70th day before Election Day. That deadline was August 25. Obama accepted his party’s nomination August 28 and McCain accepted his September 4, meaning neither could certify he was his party’s nominee by the deadline.

The Texas secretary of state’s office - the office that oversees election procedures - says the candidates filed before the deadline and supplemented their applications with additional material later.

No word yet from the Texas Supreme Court on Barr’s lawsuit. If the court rules that McCain and Obama did not meet the state’s requirements for listing their names, Texans would still be able to vote for them – by writing in their names on the ballot.

Throughout the election season, Barr has polled in the single digits. But Barr and other third-party candidates like Ralph Nader could affect the presidential race, especially in battleground states where the outcome is often decided by very small margins. For more, see “Many Political Parties Shape U.S. Political Agenda.”