Mayor Emanuel pulls ahead in Chicago race, Garcia gets backing

By Fiona Ortiz CHICAGO (Reuters) - Chicago Mayor Rahm Emanuel has opened a 10 percentage point lead in his re-election bid against Jesus "Chuy" Garcia, an opinion poll on Sunday showed, though his challenger received a hard-won labor union's endorsement that could bring in campaign cash and volunteers. The Chicago mayor's race went to an unprecedented run-off when well-funded Emanuel, mayor since 2011, failed to clinch the 50 percent of the vote he needed for an outright win