The ink is barely dry on a U.S. Circuit Court ruling calling the National Day of Prayer unconstitutional and already court-watchers are predicting more legal action.

"I think this is destined for the Supreme Court. If the Seventh Circuit says that this judge was right, then it goes to Supreme Court of the United States," said Jay Sekulow, chief counsel for the American Center for Law and Justice, a conservative group pushing for an appeal.

If a federal judge's ruling is allowed to stand, this year's National Day of Prayer will likely be the nation's last. U.S. District Judge Barbara Crabb ruled on Thursday that the federal proclamation violates the constitutional ban on government-backed prayer. "[I]ts sole purpose is to encourage all citizens to engage in prayer, an inherently religious exercise that serves no secular function," she wrote.

The case was brought by members of the Freedom from Religion Foundation, a group of atheists and agnostics in Wisconsin. They say their message to the government is clear. "We want you to keep out of the religion business. It's not an appropriate proclamation," said Annie Laurie Gaylor, one of the plaintiffs. "You should not be asking constituents to pray. You do not have the power to ask constituents to pray and to tell them what to pray for and to set aside a day for prayer."

The Justice Department is now reviewing the ruling but it appears this year's observation on May 6 is safe. According to a Tweet by the White House on Thursday, "As he did last year, President Obama intends to recognize a National Day of Prayer." If the administration does choose to fight Judge Crabb's ruling, then no injunction would take effect until the government has exhausted its appeals - a process that could take months.

On Friday, the ranking member of the House Judiciary Committee sent a letter to U.S. Attorney General Eric Holder about the matter. Rep. Lamar Smith (R-TX) wrote, "This decision undermines the values of religious freedom that America was founded upon, and I urge the Department to appeal the ruling immediately to the Seventh Circuit."

Smith says if the ruling does stand, the ripple effect could run through all of government. "If the National Day of Prayer is unconstitutional then is it unconstitutional to have our federal Christmas holiday? Is it unconstitutional to open up every session of Congress with a prayer from the Chaplain? Is it unconstitutional to have 'In God We Trust' on our coins and money?"

Appeal or no, the next stop for the case is Congress. On Tuesday, Congressman Smith plans to introduce a resolution in the House that would support the Day of Prayer. This could also become an issue in Senate confirmation hearings for President Obama's still un-named Supreme Court nominee -- a nominee who become one of nine justices to decide the fate of this 48-year federal tradition.