Marchers had to duck into fast-food restaurants for water when they first took to Chicago's streets in support of illegal immigrants five months ago. At the next two marches, family-owned grocery stores offered free bottled water from trucks emblazoned with their names. This time, as demonstrators march from Chinatown to House Speaker Dennis Hastert's (R-Ill.) Batavia office this weekend, they will have Miller Brewing Co., as a sponsor. The brewer has paid more than $30,000 for a planning convention, materials and newspaper ads publicizing the event. The support of a major corporation for a controversial political cause shows how fierce...