A partisan conflict over voter identification is intensifying as this year's presidential election approaches. Republican state lawmakers have promoted voter-ID requirements in the name of instilling confidence in the electoral system and reducing what they argue is rampant voter fraud. The strictest laws require voters to produce an unexpired, government-issued photo ID at the polls. Studies have found little evidence of "impersonation" fraud in which someone casts a ballot under somebody else's name, but Republicans say the practice is common enough to warrant concern. Democrats, however, maintain that such fraud is rare and argue that photo-ID laws are aimed at reducing turnout by voters who lean Democratic -- including minorities, students and the elderly. Some studies show disproportionately lower ID possession among those groups, but Republicans say minority turnout in states requiring a photo ID has increased.

Peter Katel is a CQ Researcher contributing writer who previously reported on Haiti and Latin America for Time and Newsweek and covered the Southwest for newspapers in New Mexico. He has received several journalism awards, including the Bartolomé Mitre Award for drug coverage from the Inter-American Press Association and awards for investigative and interpretive reporting from the New Mexico Press Association. He holds an A.B. in university studies from the University of New Mexico.