JTA — A gun-rights activist whose YouTube output includes videos admiring Nazi firearms will be the de facto Republican nominee for a closely watched West Texas congressional district after his primary opponent, an incumbent dogged by scandal, dropped his reelection bid Thursday. Brandon Herrera, known on YouTube as “The AK Guy,” pulled more votes in this week’s primary than Rep. Tony Gonzales. The two were slated for a runoff election in May before Gonzales, now facing a congressional ethics investigation and calls from House leadership to bow out of the race, admitted to having had an affair with a staffer...