People gather to greet Rahm Emanuel at a home in Epping, N.H. on Friday. By John McCormick | Photography by Youngrae Kim for WSJ NORTH HAMPTON, N.H.—Rahm Emanuel has long been exercise-obsessed, swimming 3 to 4 miles a week, plus weight training, machine workouts and yoga. He put his vitality forward in a more public way over the weekend as he biked across a state vying to hold the first 2028 Democratic presidential nominating contest.