The principle defendants are Chief Justice John Roberts, who was scheduled to administer the oath to Obama, the Presidential Inauguration Committee (PIC), the Joint Congressional Committee on Inauguration Ceremonies (JCCIC) and the Military Inauguration Committee (MIC).

The suit Newdow v. Roberts was filed in the United States District Court for the District of Columbia on December 29. Because there was so little time before the inauguration, Newdow filed a motion for a preliminary injunction on January 5. On January 15, Judge Reggie B. Walton denied the motion, allowing the inauguration ceremony to proceed as planned.

The suit points out that the presidential oath is defined in Article II, Section I, Clause 8 of the United States Constitution: "I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my ability preserve, protect and defend the Constitution of the United States." There is a widely-held belief that George Washington added the words "so help me God" at his first inauguration, and that he has been copied in every inauguration since. But the suit asserts that there is no record of this other than a claim made 65 years after the fact, on the basis of a recollection by Washington Irving, who was six years old at the time and standing too far away to hear. The first use of "so help me God' that can be verified was the 1881 inauguration of Chester Allen Arthur. It was then used sporadically after that, and continuously only since 1933. The courts are often deferential to tradition, but this particular tradition is much more recent than its defenders claim. In fact, the practice directly violates the constitution, which specifies the oath without "so help me God."

The Inauguration Committees scheduled two prayers for the event, an invocation by Rev. Rick Warren and a benediction by Rev. Joe Lowery. The selection of Rev. Warren is particularly offensive, as Warren has said that "I could not vote for an Atheist because an Atheist says "I don't need God." The Supreme Court, in Marsh v. Chambers, has upheld prayers to open sessions of Congress because it is a separate branch of government, co-equal with the courts, and solely responsible for the conduct of its business. Newdow et al argued that the precedent that should govern this case is instead Lee v. Weisman, which held that "invocations and benedictions, even so-called nonsectarian ones ... creat[e] an identification of governmental power with religious practice,endors[e] religion, and violat[e] the Establishment Clause."

A conflicting precedent holds that "acknowledgements" of God are a "ceremonial deism" that do not violate the Establishment Clause because they "serve, in the only ways reasonably possible in our culture, the legitimate secular purposes of solemnizing public occasions, expressing confidence in the future, and encouraging the recognition of what is worthy of appreciation in society." The plaintiffs have the burden to disprove these claims. The suit demonstrates clearly that the "real meaning" is that atheists are so "inferior and degraded" that their religious views warrant no respect. Justice Scalia has even written in a SCOTUS dissent that the constitution "permits the disregard of devout Atheists."

Newdow asserted that the Invocation and Benediction violates the Establishment Clause of the First Amendment, while appending "so help me God" to the presidential oath of office violates the Establishment Clause, the Free Exercise Clause, the Due Process Clause of the Fifth Amendment, the Religious Freedom Restoration Act and the public policy stated by the Inauguration committees to unite the nation.

Judge Walton is allowing the suit to proceed, although he dismissed the request for a temporary injunction, ruling that he did not have the power to prevent Obama from making such references or inviting ministers on stage to offer prayers. Walton wrote that the plaintiffs failed to show any concrete "harm" that would result from allowing the prayers or "so help me god" to be said. Newdow et al disagree, claiming that the defendants are acting in concert to worsen the condition of Plaintiffs by identifying the government with god-belief.

In his inaugural address, Barack Obama did toss one sop to atheists, a mention of ‘nonbelievers' in a list of faith groups represented in America. But he ended his speech with a ringing "God bless you and God bless the United States of America." Clearly he feels no personal constraint against glorifying his god at government events. But perhaps, unlike his predecessor, he can be educated.