President Trump has embraced an array of far-right views and talking points in ways that have delighted many right-wing activists who have long supported those ideas.During President Trump’s first turn in the White House, right-wing extremists like the Proud Boys were on the streets, weekend after weekend, raising their voices — and oftentimes their fists — about issues such as immigration, the squelching of conservative speech and the removal of Confederate-era statues. But in the first seven months of Mr. Trump’s second term, there has been a conspicuous absence of far-right demonstrations. And that, some leaders of the movement say,...