MADISON - Wisconsin may soon be in a minority of states that don't allow voters to register online.

The state, long considered a model for its high voter turnout and election administration, seems stubbornly old-fashioned as it sticks to paper registration while others move to online systems that are simpler, cheaper and less prone to errors, elections experts told lawmakers recently.

Legislators from both parties have expressed interest in online registration, but progress has been stymied by a longstanding fight over same-day voter registration and other party divisions. Two bills that would have allowed online voter registration have failed to pass in the past four years, frustrating elections officials.

"Online registration is no longer cutting-edge innovation, it is a well-established and essential tool," said Kevin Kennedy, director of the Government Accountability Board, which oversees Wisconsin's elections. "We already have in place what we need to do. We need the legislative authorization to do this."

Eighteen states have already adopted online registration, with Arizona pioneering the approach in 2002 and others following since 2007. Four states have approved the method and are working on the systems. Fifteen more states, including Wisconsin, are considering legislation, according to data from the National Conference of State Legislatures.

Rep. Terese Berceau, D-Madison, has pushed to pass a bill that would allow the Government Accountability Board to create a system permitting voters to register online, with data to be checked with records in other state databases.

The system would allow voters with a driver license or other identification to update addresses or names and register to vote up to three weeks before an election.

"I would have liked to have been on the cutting edge," Berceau said. "...But we've got the textbook now."

A form of the bill allowing online registration failed last session after Republicans, who control the Legislature, wrapped it into a larger piece of legislation that would have also changed campaign finance law.

A similar online registration bill also failed in 2010 after Democratic leaders who then controlled the Legislature said it was introduced too late. Republicans opposed that bill, saying it would have paved the way for voter fraud.

Data that the Pew Charitable Trusts presented to lawmakers at a hearing last week show voters from both parties register online in numbers that reflect their states political makeup.

Online registration also has helped states and municipalities cut costs. Tammy Patrick, an elections officer in Arizona, said Maricopa County alone saved about $1.4 million between 2008 and 2012. It costs the county just 3 cents to register voters online, as opposed to 83 cents on paper, she said.

California saved $2.34 per online registrant and $2 million in a single month around the 2012 presidential election, according to Pew data.

Wisconsin has estimated it would cost about $600,000 to institute online voting, but the system would save about $1.7 million over the next decade, after taking into account costs for publicizing the method.

David Becker, director of election initiatives of the Pew Charitable Trusts, and others said online registration also may be less prone to errors than the current pen and paper system that requires voters to write down personal information that is later entered into a computer system manually.

Rep. Kathy Bernier, R-Lake Hallie, said she supports online voter registration but has some broader elections fraud concerns she'd like addressed in any legislation she is asked to sign off on. Bernier said she's willing to work on a bipartisan bill and help convince other lawmakers - namely Senate Elections Committee chairwoman Mary Lazich - that it's time to update the system.

Lazich, a New Berlin Republican, did not respond to multiple requests for comment from The Associated Press.

Other Republicans said they won't support online registration unless lawmakers scrap same-day registration, which elections officials say is used widely across the state, including in heavily Democratic areas like Milwaukee and Madison.

"Why would you also provide another layer of logistics and costs by allowing same-day in person?" asked Rep. David Craig, a Big Bend Republican who said his "No. 1 goal is saving the state money."

Bernier said the state shouldn't need to get rid of same-day registration in order to adopt online registration, and Rep. JoCasta Zamarripa, D-Milwaukee, said such a move would be a deal-breaker.

A 2013 GAB report on the cost of getting rid of same-day registration showed it would cost taxpayers between $13.1 million and $14.5 million.

Just three online voter registration states - Minnesota, Colorado and Connecticut - also allow voters to register the day of an election. But no states with same-day voter registration eliminated it when they instituted online registration.