OKLAHOMA CITY — The debate over a voter identification bill the Legislature has sent to Gov. Brad Henry has been marked by lofty rhetoric.

Republicans have said it is badly needed to protect “the sanctity of the ballot box,” and Democrats have opposed it as infringing on “the precious rights of voters” to have easy access to the polls.

But who gains or loses political advantage from the bill and similar measures in other states is central to the partisan passions that have been whipped up across the country about the issue, experts say.

Critics say there is no reason for the bill, other than to throw up administrative roadblocks to some voters, especially those prone to vote for Democrats — the elderly, the disabled and minorities.

“This bill will not disfranchise anybody,” Sen. John Ford, R-Bartlesville, said as his measure came under attack last week from the several groups, including the American Association of Retired People, after winning final approval in the House.

Ford acknowledges he is “not aware of any major voter fraud” in Oklahoma, but said his bill is needed as “a pre-emptive step to keep voter fraud from starting.”

The bill requires voters to present a government-issued photo identification or their voter ID card at the polls. Ford said it is not an onerous requirement because voters can cast provisional ballots if they forget to bring identification.

The nonpartisan League of Women Voters disagrees, however, and is urging Henry, a Democrat, to veto the bill. The group says the bill is not needed.

“If there were any evidence of voter impersonation in Oklahoma elections, the League of Women Voters would be first in line supporting this kind of legislation, but proponents cannot identify one single case,” said Gloria Caldwell, League spokeswoman.

Caldwell said the estimated $1 million it would cost to administer the bill is “an irresponsible expenditure” when the state faces a huge revenue shortfall that threatens to cut budgets of schools and other critical services.

The measure passed Oklahoma Senate on a 25-21 party-line vote almost a month ago, with Republicans voting for it and Democrats against it. The GOP has a 26-22 edge in the 48-member chamber.

Surprisingly, it was approved without debate in the House by a 71-27 margin last Wednesday. Eleven Democrats voted for the bill in the 101-member body, where the GOP has a 61-40 majority.

The ease and speed with which the measure got through the Oklahoma Legislature contrasts with nearby Texas, where a voter ID bill was the subject of a 23-hour-long Senate hearing before passing on a party-line vote. It now faces action in the House, where the GOP has only a slight edge.

Officials of the Brennan Center for Justice at the New York University school of law went to Austin to testify about the GOP voter plan in Texas. The center estimates about 11 percent of voters nationwide — about 21 million Americans — do not have photo ID’s and could be harmed by such legislation.

The center’s Adam Skaggs, in a March 17 article for the organization, wrote that allegations of voter impersonation fraud had been “definitively debunked” and referred to a study that said antiquated voter registration systems are a problem, keeping 2 to 3 million people from voting in 2008.

“The only reason lawmakers can have for fighting about voter ID when real problems are costing million of Americans the right to vote is because they like having voter ID around as a politically divisive wedge issue they can exploit to partisan advantage,” Skaggs said.

Ford said polls show voter identification laws are popular with the public and denied partisan intent.

“I don’t know if either party would be helped — and if either one is — I don’t know which party it would help,” he said.

Sen. Jim Wilson, D-Tahlequah, said there is a reason the voter ID bills are being pushed by Republicans in several states.

“They have had this on their agenda for years because it does discourage people from voting — the seniors, the minorities, poor people and the disabled,” he said.

Wilson said it is estimated in Oklahoma there are 78,000 people without a photo ID. “Those will primarily be Democratic constituents, many people who use government services,” he said.

Paul Sund, spokesman for Henry, said the Democratic governor shares concerns expressed by the League of Women Voters, the AARP and other nonpartisan groups that oppose voter identification laws.

“As noted by the League, some registered voters, including many senior citizens, do not have easy access to appropriate identification and could be discouraged from participating in the electoral process,” Sund said.

He said Henry would examine both sides of the issue before making a decision by this Wednesday on whether to sign or veto the bill.