WASHINGTON — Republican Mike Johnson is the new speaker of the House, but the ally of Donald Trump inherits many of the same political problems that have tormented past GOP leaders, tested their grasp of the gavel and eventually chased them out of office.When the House convenes Thursday it will be a bustle of activity, making up for lost time during the weeks of chaos since the ouster of Kevin McCarthy. But the goodwill toward Johnson blurs the political fault lines challenging the Louisianan’s ability to lead …