Imagine: You're country music's hottest band, you just sold $49 million in tickets in a single day, and you hauled away enough Grammys to fill a long-bed pickup. Then your wild-child lead singer up and shouts that she's ashamed of President Bush. If the Dixie Chicks' Natalie Maines had to holler something really stupid in London, why couldn't it have been, "Thank you, Detroit?" Now the Erwin sisters -- founders and fearless leaders of what began as a Dallas teen-agers' fiddle band -- will never get away. Maybe it was simple grandstanding that inspired Maines, 28, a Lubbock native, to...