WASHINGTON (Legal Newsline)-All of the nation's state attorneys general have signed onto a brief to include references to God in President-elect Barack Obama's inauguration this month.

Authored by Texas Attorney General Greg Abbott, the amicus brief was filed with the U.S. District Court for the District of Columbia in the case of atheist Michael Newdow v. Supreme Court Chief Justice John Roberts.

Newdow, a Sacramento physician, seeks to eliminate prayer from the inaugural ceremony and prevent Obama from being able to say "so help me God" in the presidential oath of office.

U.S. District Court Judge Reggie Walton set a hearing for Jan. 15.

The lawsuit claims that prayer and an oath of office that includes the words "so help me God" violate the First Amendment's Establishment Clause.

Abbott, a Republican, said Obama has a constitutional right to invoke God at his inauguration ceremony.

"Since President George Washington uttered the words 'so help me God' at his first inauguration in 1789, American presidents have a longstanding, historic tradition of invoking the Almighty at their inaugural ceremonies," Abbott said.

"Despite more than two hundred years of established tradition - and no legal precedent for their challenge - a group of activists have asked the courts to interfere with President-elect Obama's right to pray and invoke God during his inauguration as 44th president of the United States," he added.

Newdow is perhaps best known for his efforts to ban recitations of the Pledge of Allegiance in public schools because of the phrase "under God."

The 9th U.S. Circuit Court of Appeals found that the phrase violates the Establishment Clause of the First Amendment to the United States Constitution. The decision was later overruled by the U.S. Supreme Court on procedural grounds.

From Legal Newsline: Reach reporter Chris Rizo at chrisrizo@legalnewsline.com.