Updated

The possibility that President Obama could send the self-professed mastermind of the Sept. 11 attacks to a military tribunal has earned him the highest insult from the left -- that he's another George W. Bush.

A full-page ad in Sunday's New York Times left no doubt as to how the American Civil Liberties Union feels about the possibility of the president reversing the decision to send Khalid Sheikh Mohammed and his alleged co-conspirators to civilian court.

"What will it be Mr. President?" the ad asks in boldfaced type. "Change or more of the Same?"

In the middle of those words are four photos that show Obama's face morphing into Bush's.

"Many of us are shocked and concerned that right now, President Obama is considering reversing his attorney general's decision to try the 9/11 defendants in criminal court," the advertisement continues. "Our criminal justice system has successfully handled over 300 terrorism cases compared to only 3 in the military commissions."

The ad follows a series of reports that reflect a softening of the administration's position that the accused Sept. 11 architects must be tried in federal court instead of military tribunals.

The public softening is part of a test, a source told Fox News, to gauge how infuriated the left would be by reversing course. The White House knows Republicans like the idea of the tribunals being used -- and needs their support on other key national security matters -- but a shift on this issue could poison the waters between the president and the liberal base, as demonstrated by the ACLU ad.

"As president, Barack Obama must decide whether he will keep his solemn promise to restore our Constitution and due process, or ignore his vow and continue the Bush-Cheney policies," the ACLU ad said.

Republican Sen. Lindsey Graham, R-S.C., speaking on CBS' "Face the Nation," said the ACLU ad was out of line.

"The president is getting unholy grief from the left," said Graham, who supports moving the defendants to tribunals. "The ACLU theory of how to manage this war I think is way off base."

Some are urging groups like the ACLU to look at the bigger picture.

Attorney General Eric Holder announced in November that the defendants would be heading to Manhattan civilian court, but that move has generated a huge backlash from New Yorkers, including the mayor and police chief, as well as Republicans in Congress. The backlash has forced the administration to reconsider not just the location of the trial but the forum.

"Foreign terrorists ought not to be tried in U.S. courts. Period," Senate Minority Leader Mitch McConnell told Fox News. "They ought to be taken to Guantanamo, detained there, interrogated there and adjudicated there in military tribunals."

A source told Fox News that if the administration decides to send the case back to the commissions, it could be part of a larger bargain to get support to close the detention center at Guantanamo Bay and bring those detainees to the U.S. Congress has barred the transfer of prisoners who don't have a path to trial -- those who appear to be detained indefinitely -- and refused to give the president the money for a facility to house them on American soil.