These tots may not care about the larger issues of the presidential campaign, but they were more than happy to join the fun on Saturday when Brooklyn’s largest handmade American flag was unfurled in Prospect Park. Some park-goers had a knee-jerk reaction that the flag-waving was a rally for John McCain, but it was actually the work Mending Bee for Change, a group that supports Barack Obama and wants to “take back” the American flag — “the flag of the American Left,” said David Mahfouda.