Hillary Clinton is coming under increasing pressure from progressives to oppose the Dakota Access oil pipeline. Nearly a month after the Obama administration halted its consideration of an easement for the project, activists want to know why she has remained silent. Polls show Clinton is struggling to win over millennial supporters of her former rival, Sen. Bernie Sanders, who has come out in strong opposition to the North Dakota-to-Illinois pipeline. American Indians say the project would endanger water supplies for people of the Standing Rock Sioux reservation. Dakota Access is a tough issue for Clinton, as major unions support the project just as they backed Keystone. Opposition to the new pipeline would put Clinton in direct confrontation with unions.