While hundreds of thousands of poor migrants seeking asylum in the U.S. have trekked on foot from South and Central America in the last eight months, there has also been a rise in middle class migrants flooding the southern border. These so-called middle class migrants often fly to Mexico's northern border on pre-planned flights and cross into the U.S. by cab or another car hire, a Border Patrol chief in Arizona told the Wall Street Journal. 'They got off the plane and went to a cab or to a bus,' Chris Clem, Border Patrol's chief patrol agent in Yuma, said....