Former US President Barack Obama on Friday delivered one of his sharpest critiques yet of Donald Trump’s administration, warning that core American values are under threat and calling out what he sees as a dangerous silence from Republican leaders. Speaking at Hamilton College in New York, Obama said he is “deeply concerned” by actions from the White House — from its crackdown on student protesters and universities to its pressure on law firms and the press — arguing that such behavior would never have been tolerated from any of his predecessors. “It’s unimaginable that the same parties that are silent...