BY JULIE PACE

Associated Press

WASHINGTON

--A robust registration push by President Barack Obama's re-election campaign has resulted in more Democrats than Republicans on the voter rolls in most battleground states, including Florida and Nevada, according to data from state election boards.

But Republicans have had their own registration success, narrowing the Democratic voter advantage since 2008 in many of the battlegrounds, including Iowa. And party officials say they have put more resources into persuading independent voters who are already registered to cast their ballots for party nominee Mitt Romney.

"We do not put as big an emphasis on voter registration programs as we do in talking to and persuading independents," said Rick Wiley, political director for the Republican National Committee. "I would prefer to go in and talk to an independent who is already registered. They have a voter history."

Obama campaign manager Jim Messina said his campaign "can do both things--both persuade the undecideds and get out our voters."

The Democratic campaign also says a deeper look at the registration numbers shows an uptick in new Hispanic voters and voters under the age of 30--voting blocs where the president has an advantage.

Obama's registration and get-out-the-vote operations in 2008 played a crucial role in his getting elected. With the White House race tightening less than four weeks from Election Day, the Democratic campaign is banking on its organization in the battleground states to give Obama an edge.

Deadlines to vote in the November election have passed in many states, but the registration totals are expected to shift somewhat in the coming days as last-minute entries are counted.

The most current data, available from state election boards, give Democrats a registration advantage in most of the battleground states with party identification: Florida, Iowa, North Carolina and Nevada. The party also significantly outpaces Republican registration in Pennsylvania by more than 1 million voters. That's part of the reason Romney's campaign has not made a serious effort to compete in the state.

Republicans have a voter registration advantage in Colorado and New Hampshire.

Voters in three other battleground states--Ohio, Virginia and Wisconsin--do not register with a party when they sign up to vote.

Of course, voter registration totals don't tell the whole electoral story in many states.