The Bush administration found a key ally on Capitol Hill Monday as it broadened its aggressive defense of a recently revealed domestic spying program that used warrantless surveillance. Sen. Pat Roberts of Kansas, the chairman of the Senate Intelligence Committee, “believes the program is consistent with U.S. law and the Constitution,” Sarah Little, Roberts’ spokeswoman, said in an e-mailed statement. Roberts, in his first public remarks on the electronic surveillance program, indicated he has known about the program since he took over the committee in 2003. He said he believes the administration has taken proper safeguards to preserve Americans’ civil...