The New York Times reports 45 of 47 GOP senators voted for a stipulation in the 2012 military authorization bill that would ban civilian trials for "enemy combatants" who are not American citizens accused of plotting attacks.
The White House opposes such a broad rule, which would also represent a shift to the right from the policies of former President George W. Bush, the Times noted. Bush relied on the civilian criminal justice system in some terror cases and the military system in others, and Obama has as well.
At the same time, liberal criticism of military detentions and trials for terror suspects has diminished.
"The goal posts are moving," said Robert Chesney, a law professor at the University of Texas at Austin. "In the Bush years, there was little complaint from the right about keeping both civilian and military options -- least of all for persons captured in the U.S. But now the congressional Republican consensus is moving toward a monolithic military approach, to the point where things Bush did would today be denounced as weak."
John O. Brennan, Obama's top counter-terrorism official, said the administration would stick to its "firm position" that civilian courts handle domestic terrorism cases.
And last week, Jeh C. Johnson, the Pentagon's general council, warned in a speech against allowing "the U.S. military to extend its powerful reach into areas traditionally reserved for civilian law enforcement in this country."
In the House, GOP lawmakers have criticized the Obama administration for trials of terror suspects in civilian courts, including a decision to charge a Somali man in New York after detaining him on a ship and interrogating him for two months.
But the Times said it remains uncertain whether the GOP presidential nominee would share the view of Republican lawmakers, as the issue has hardly come up in campaigns of 2012 candidates.