Illinois Gov. Bruce Rauner (R_ (Justin Fowler/The State Journal-Register via AP File)

Locked out of power in much of the country, Democrats celebrated a victory today in the fifth most populous state when Gov. Bruce Rauner (R-Ill.) signed automatic voter registration into law.

“I think we have a good, strong piece of legislation that makes it easier for everyone who’s eligible to vote to be able to vote,” Rauner said in a signing statement, thanking Democrats who amended a bill that he’d once opposed.

And by signing on, Rauner made Illinois the 10th state to start implementing “AVR,” which in just two years has become a defining cause for progressive activists. Progressive think tanks have sold the idea as a cheap way to increase voter turnout. Democrats see it as a way to increase their margins with voters likely to agree with them, but unlikely to take time to register. Our Revolution, the activist group launched by Sen. Bernie Sanders (I-Vt.), is pressuring legislators to endorse Sanders’s national AVR bill, which like most progressive bills is stalled.

“If we believe in a vibrant democracy, we need to have the highest voter turnout in the world,” Sanders said last year, after Vermont joined the shortlist of AVR states. “Enough with cowardly politicians protecting themselves by suppressing the vote.”

Illinois is just the second state where Republican leadership has signed off on AVR; the first was Georgia, where in just four months of AVR, close to 600,000 people registered to vote. Oregon’s law, which went into effect last year, is seen by progressives as the model. It’s “opt-in,” meaning anyone who interacts with the state’s Department of Motor Vehicles is registered, unless he or she asks not to be. And it was promoted by Gov. Kate Brown (D-Ore.), a former secretary of state who rose to the governor’s office when her predecessor resigned due to scandal, and who previously championed the state’s vote-by-mail program. In 2016, Oregon’s voter turnout rose by 4.1 percent, higher than any other state.

“I think we should be fighting like hell to make sure that we make voting more accessible to more Americans,” Brown said in an interview with the Post earlier this year, after she appeared at the semiannual Democracy Alliance donor conference. “We’re literally using the data from the DMV and handing it to the secretary of state’s office to register voters.”

The increased turnout did not lead to Democratic victories up and down the ballot; Oregon Democrats actually lost ground in the state legislature, and lost control of Brown’s old office. But a study by Demos, a progressive think tank which supports AVR, found that the population of voters who came onto the rolls automatically was less white than the population registered under the opt-in system.

That could matter greatly in Illinois, a onetime swing state that now votes strongly Democratic in presidential elections, but sees turnout fall drastically in midterms. In 2014, Rauner won his gubernatorial race with just 1,823,627 votes. Two years later, Donald Trump won 2,146,015 votes in Illinois’s presidential race, good enough only to lose to Hillary Clinton, in her home state, by a 17-point landslide.