There is growing talk on the right of replacing Donald Trump, the Republican Party’s presumptive nominee for president, and even chatter about a possible alternative. As Trump has floundered over the past week after questioning a federal judge’s impartiality because of his Mexican ancestry, Trump’s critics within the GOP have stepped up their efforts to thwart him. Some anti-Trump conservatives, who have tried for months to recruit an independent candidate, have begun looking more closely at attempting to persuade delegates at next month’s GOP convention to nominate someone other than Trump. “There is a rapidly moving train toward the convention...