SummaryTrump order targeted children of certain immigrants Three judges issued orders blocking policy nationwide Administration challenges nationwide injunctions WASHINGTON, May 15 (Reuters) - The U.S. Supreme Court wrestled on Thursday over Donald Trump's attempt to broadly enforce his executive order to restrict birthright citizenship, a move that would affect thousands of babies born each year as the Republican president seeks a major shift in how the U.S. Constitution has long been understood.The court's conservative justices, who hold a 6-3 majority, seemed willing to limit the ability of lower courts to issue nationwide, or "universal," injunctions, as federal judges in Maryland,...