Whether the regulation meets the "narrowly tailored" requirement is of course a question of law, to be reviewed by an appeIlate court de novo. See, e.g., White House Vigil v. CLark, 746 F.2d at 1529. This court has characterized "the test of'narrow tailoring' ... as a balancing test, inquiring whether the restriction 'burdens more speech than is necessary to further the government's legitimate interests.' " Henderson v. Lujan, No. 91-5258, slip opinion ("slip op.") at 9 (D.C. Cir. May 22, 1992) (quoting Ward, 491 U.S. at 799).