Updated from 7:21 a.m. ESTPresident Bush nominated U.S. Appeals Court judge and former federal prosecutor Samuel Alito to the Supreme Court Monday, calling him a thoughtful jurist with a "deep understanding of the proper role of judges in society." Alito, whose nomination will please conservatives and could ignite a contentious confirmation process in Congress, was named to fill the seat being vacated by the retiring Sandra Day O'Connor. Bush's last nominee for the seat, Harriet Miers, withdrew her name last week. In announcing the nomination, Bush stressed that Alito has twice been unanimously confirmed by the Senate, first as U.S. attorney for New Jersey and later to the appeals bench. "He's won admirers across the political spectrum," Bush said. "I urge the Senate to act promptly on this important nomination and return an up or down vote by the end of the year." Early reaction from Democratic lawmakers was cautious. Senate Minority Leader Harry Reid, a Democrat from Nevada, said: "The Senate needs to find out if the man replacing Miers is too radical for the American people." Alito, 55, was named to the federal appeals bench by President Bush's father in 1990. He is a graduate of Princeton University and the Yale Law School. In announcing his nomination Monday, the president stressed Alito's credentials, saying he had "more prior judicial experience than any Supreme Court nominee in more than 70 years." That experience could also prove an obstacle in the confirmation process. Among other things, Democrats on the judiciary committee are certain to focus on a 1990s vote in which he backed a Pennsylvania law that would have required a woman to notify her husband before receiving an abortion. The law was struck down.