The activist organization ACORN on Tuesday defended its voter registration practices amid new allegations of voter registration fraud.
In Ohio, Democrat Barack Obama said the GOP shouldn't use the group's registration problems as an excuse to keep voters from turning out on Election Day.
The Association of Community Organizations for Reform Now says it has registered 1.3 million young people, minorities and poor, and working-class voters.
Some of those registration cards have become the focus of fraud investigations in Nevada, Connecticut, Missouri and at least five other states.
More than 13,000 workers in 21 states recruited less-fortunate voters, who tend to be Democrats.
“The vast, vast majority were dedicated workers,” ACORN spokesman Kevin Whelan said.
Republican John McCain's campaign Tuesday said Obama should rein in ACORN's efforts. The campaign accuses the Democratic presidential candidate of having close ties to the group.
Obama and two other lawyers represented ACORN in 1995 in a lawsuit against the state of Illinois to make voter registration easier. During this year's primary, Obama hired a firm with ties to the group for a get-out-the-vote effort.
Obama said ACORN isn't advising his campaign on voter registration.