MADISON, Wis. — The U.S. Supreme Court on Monday turned away a challenge to Wisconsin’s voter identification law, allowing the law to stand and handing a victory to Gov. Scott Walker following a long fight by opponents who say it’s a thinly veiled attempt to make it more difficult for Democratic backers to vote. The law won’t be enforced for an April 7 election because it’s only two weeks away, but it will be in subsequent elections, the state attorney general said. Walker, a likely …