LOS ANGELES - More than 1 million mostly Hispanic immigrants and their supporters skipped work and took to the streets Monday, flexing their economic muscle in a nationwide boycott that succeeded in slowing or shutting many farms, factories, markets and restaurants. From Los Angeles to Chicago, Houston to Miami, the "Day Without Immigrants" attracted widespread participation despite divisions among activists over whether a boycott would send the right message to Washington lawmakers considering sweeping immigration reform. "We are the backbone of what America is, legal or illegal, it doesn't matter," said Melanie Lugo, who with her husband and their third-grade...