By MICHAEL WEISSENSTEIN
Associated Press Writer
August 31, 2004, 1:25 AM EDT
NEW YORK — Police braced for a day of civil disobedience Tuesday after an ugly turn in relations between Republican National Convention protesters and the thousands of officers assigned to police them.
A march from the United Nations to Madison Square Garden ended in violence after a protester attacked a plainclothes detective, knocking him unconscious and leaving him hospitalized, according to police and witnesses.