Michelson, a former Zoning Board member who is promising to stand up to developers amid citywide complaints about congestion, overcrowding and lack of zoning enforcement, first indicated he would challenge Democratic incumbent Mayor David Martin a month ago. The 40-year resident of Stamford first rose to prominence when he clashed with Harbor Point developer Building and Land Technology over its plans to replace the boatyard it tore down in violation of its zoning agreement with the city.