Mitt Romney has not announced whether or not he’ll make a second run for the White House, but his former aides are staying in campaign shape by managing key races across the nation that could benefit their old boss in future elections. In at least six crucial races around the country, veterans of the former Massachusetts governor’s presidential campaign are working to guide new candidates to victory. It may appear a simple case of political professionals moving to new clients, but Romney’s team has kept in close contact should a second presidential campaign come to fruition. That could pay off,...