So much for the hope that the Million Man March could pass without a grotesque backlash. An organization calling itself “American Whites” is e-mailing America Online subscribers asking Caucasians to “support the first ever “White Out’ ” on Oct. 16. While Nation of Islam Minister Louis Farrakhan leads black men to the Mall for a day of “atonement,” American Whites —whose mailing address is a Stafford, Va., post office box—wants its followers to boycott D.C. If we’re really lucky, American Whites’ admirers will stay away from the District on Oct. 16, and on every day thereafter.