WASHINGTON (AP) — A Hispanic Roman Catholic theologian who advised Barack Obama’s presidential campaign is the Obama administration’s choice to serve as U.S. ambassador to the Vatican. The White House announced Wednesday it plans to nominate Miguel H. Diaz, an associate professor of theology at the College of Saint Benedict and Saint John’s University in Collegeville, Minn., for the post. Diaz, 45, a Cuban-American, was a member of the Obama campaign’s Catholic advisory board. Diaz was among 26 Catholics who signed a statement supporting the nomination of Health and Human Services Secretary Kathleen Sebelius, a Catholic whose support for abortion rights was criticized by conservative Catholics.