Attorney General Eric H. Holder Jr. yesterday overturned a Bush administration ruling in January that immigrants do not have a constitutional right to effective legal counsel in deportation proceedings. In vacating the decision his predecessor, Michael B. Mukasey, issued two weeks before President George W. Bush left office, Holder restored one of the most common grounds cited by immigrants for appealing removal orders: that their attorneys were incompetent. ....immigration courts are separate from the judicial branch and operate under the Justice Department, which makes the U.S. attorney general the final arbiter for immigration proceedings. Immigrants are not entitled to public...