Barack Obama took time out from debate preparations today to weigh in on the increasingly loud controversy over an activist group's voter registration drive. The Association of Community Organizations for Reform Now, known as ACORN, claims to have registered 1.3 million young people, minorities, and working-class voters. But some of those registration cards have listed dead or nonexistent people and are being investigated in at least eight states. Republican John McCain, and today his running mate Sarah Palin, have called on Obama to take control of ACORN's activities. “Obama has a responsibility to rein in ACORN and prove that he...