Six months before a presidential election in which turnout could matter more than persuasion, the Republican Party, the Trump campaign and conservative activists are mounting an aggressive national effort to shape who gets to vote in November — and whose ballots are counted... ...The Republican program, which has gained steam in recent weeks, envisions recruiting up to 50,000 volunteers in 15 key states to monitor polling places and challenge ballots and voters deemed suspicious. That is part of a $20 million plan that also allots millions to challenge lawsuits by Democrats and voting-rights advocates seeking to loosen state restrictions on...