Will New Voter ID Laws Protect the Polls or Suppress Turnout?

Republicans now control legislatures in more than half the states and, in many they're passing laws requiring voters to bring state-issued photo-identification to the polls. Are they really trying to prevent voter fraud or keep supporters of Barack Obama away from the polls? Do Democrats have real proof that minorities, old people and college students can't produce state-issued picture ID's? We hear a debate that's raging in state legislatures across the country.