– After nearly five years of partisan feuds over state elections laws, there are growing signs that lawmakers are finding common ground on both sides of the aisle, in blue and red states alike.

During legislative sessions this year, several states enacted changes designed to ease the voting process, such as online voter registration and same-day registration. When ­Illinois finishes the rollout of its online system this summer, more than 100 million eligible voters will live in states offering online registration — about half of the nation’s eligible voters, according to the United States Elections Project.

The new measures come on the heels of a bipartisan presidential elections commission report released in January that encouraged states to “transcend partisan divisions and view election administration as public administration that must heed the expressed interests and expectations of voters.”

Restrictive measures, such as voter ID requirements, spiked following the 2010 elections, spurred in part by GOP takeovers around the country. Some of these efforts continue. In response, many Democrats pushed laws in 2013 to ease ­voting in states they controlled.

“In 2011 and 2012, there was a wave of restrictive laws that were passed,” said Jonathan Brater, lawyer for the Brennan Center for Justice’s Democracy Program. “Compared to that period, this is more of a mixed bag, and we’re certainly optimistic that more states are going to be moving to make voting easier.”

The momentum and bipartisan cooperation this year have been most evident in online registration efforts. “That is the story this year,” said Wendy Underhill, who follows elections for the National Conference of State Legislatures.

More than half the states now have some form of online voter registration or have approved legislation to launch a system, according to an NCSL tally.

Lawmakers passed measures this year to approve online registration in officially nonpartisan Nebraska and the Democratic states of Massachusetts and Minnesota. Voter registration also went online in recent months in Virginia and GOP-controlled Georgia and Democratic-controlled Delaware and Connecticut. Virginia was GOP-led in 2013 when its legislation was passed.

Illinois, heavily Democratic, is expected to have its system, which was approved in 2013, operational in a few months. Last year, West Virginia also approved systems that have yet to launch.

Hawaii’s Democratic legis­lature approved same-day voter registration, and the bill is awaiting Gov. Neil ­Abercrombie’s signature. This would make it the 11th state, plus the District of Columbia, to allow it. Nebraska and GOP-controlled Utah also approved limited same-day registration measures this year.

“The common-sense reforms that have been passed in other states are either coming online or moving forward in new states,” said Lenore Palla­dino, vice president of policy and outreach at Demos, which advocates for voting rights. “Legislators across the board do see that as something they want to pursue.”

Reasons for the widespread popularity of online voter registration vary across states. Demo­crats often get on board with proposals aimed to make the voting process easier. Republicans have been enticed by arguments that a digital registration system can be more secure. And the prospect of making changes that have saved some states millions of dollars has played well in many capitals.

California’s move to online registration saved $2.5 million, while officials in Maricopa County, Ariz., which includes Phoenix, reported saving nearly $1.4 million from 2008 to 2012, according to an Elections Initiative report from the Pew Charitable Trusts.

“It’s being adopted in red states and blue states. It’s just taking off everywhere,” said Barry Burden, a professor at the University of Wisconsin- Madison.