Michigan Rep. Justin Amash became the first Republican lawmaker to declare that President Donald Trump committed impeachable offenses and that Attorney General William Barr “deliberately misrepresented” special counsel Robert Mueller’s report. Amash, whose libertarian views often put him at odds with Trump and his fellow Republicans, posted a series of tweets Saturday afternoon outlining positions that even some Democrats have been unwilling to embrace — an extraordinary development that comes as Democratic leaders face increasing pressure from progressives to launch impeachment proceedings. “Contrary to Barr’s portrayal, Mueller’s report reveals that President Trump engaged in specific actions and a pattern of...