DETROIT — New numbers from Public Policy Polling show Rand Paul has a slight edge over a crowded field of Republican contenders in very early numbers for the 2016 primary. The poll showed 18 percent of primary voters in Michigan say he would be their first choice for 2016, followed by Jeb Bush at 16 percent, Chris Christie at 15 percent, Paul Ryan at 12 percent, Marco Rubio at 11 percent, Ted Cruz at 7 percent, Rick Santorum at 6 percent, Bobby Jindal at 4 percent, and Susana Martinez with less than 1 percent. On the Democratic side, recent polls...