UNIVERSITY PLACE, Pierce County — Floyd Brown lumbered his 6-foot-6 frame through the doorway at a small cafe here and ordered two coffees. The woman at the counter craned her neck until she met his eyes. "My!" she exclaimed. "You block out the sun." She couldn't have known how deeply her observation might resonate with the many Democrats whose political aspirations the longtime conservative operative has tried to sink. Brown, 47, is known best for creating a controversial television ad that helped derail Michael Dukakis' presidential run in 1988 by linking the former Massachusetts governor to a prison-furlough program and...