President Trump nominated federal appeals court Judge Brett Kavanaugh to the Supreme Court Monday night, setting up a furious partisan confirmation battle as he seeks to move the high court firmly under conservatives’ control for decades to come. In a prime-time announcement at the White House, the president tapped Judge Kavanaugh of the Court of Appeals for the D.C. Circuit after a 12-day whirlwind search to replace the retiring Justice Anthony M. Kennedy. “Judge Kavanaugh has impeccable credentials, unsurpassed qualifications, and a proven commitment to equal justice under the law,” Mr. Trump said as he introduced the nominee and his family. “There is no one in America more qualified for this position and no one more deserving.” Judge Kavanaugh, 53, has served on the appeals court since 2006, ruling on some of the nation’s most high-profile cases on a court that is considered a steppingstone to the Supreme Court. He is a favorite of the conservative Washington legal establishment.