WASHINGTON (Reuters) -Republican U.S. Senator Lisa Murkowski disclosed this week that the threat of political retaliation from President Donald Trump is real enough to make her anxious about speaking out about his tariffs, executive orders and cuts to federal agencies. "We are all afraid," Murkowski told a summit of nonprofit and tribal leaders in her native Alaska. White House spokesperson Taylor Rogers said in a statement: "President Trump's only retribution is success and historic achievements for the American people."