WASHINGTON, March 22 - Battle lines were drawn Tuesday in the debate over the government's counterterrorism powers, as an unlikely coalition of liberal civil-rights advocates, conservative libertarians, gun-rights supporters and medical privacy advocates voiced their objections to crucial parts of the law that expanded those powers after the attacks of Sept. 11, 2001. Keeping the law intact "will do great and irreparable harm" to the Constitution by allowing the government to investigate people's reading habits, search their homes without notice and pry into their personal lives, said Bob Barr, a former Republican congressman who is leading the coalition. Mr. Barr...