When Richard Martin was convicted of felony drug possession two decades ago, he decided it was time to get clean and get a job. Getting clean was hard. Getting a job was even harder.

He was a 40-year-old recovering addict with an erratic work history and a felony conviction. Most private employers wouldn’t even look at his resume. He got a job as a teacher, but then had his teaching license revoked when the state discovered his conviction. He eventually earned a master’s degree, found work in the nonprofit sector and has never again had trouble with the law. But he knows he is lucky.

“It was terribly hard when I first got out,” said Martin, now 58. “You feel like the civilized world doesn’t really want me, and maybe they’re right, I should be with people like me.”

On Tuesday, California voters will decide on a ballot measure that could make it a little bit easier for people like Martin to find jobs. Proposition 47 would reclassify some drug and property crimes as misdemeanors rather than felonies. Proponents of the measure have focused primarily on the cost savings from sending fewer people to prison, but they argue it would also help non-violent offenders like Martin become productive members of society.

Opponents counter that any benefits aren’t worth the tradeoffs. The initiative would reclassify possession of date-rape drugs and the theft of many firearms as misdemeanors, which some law enforcement officials argue could result in the release of violent or potentially violent offenders.

But beyond the specifics of Proposition 47, there is an emerging consensus from across the political spectrum that some sort of reform is necessary to help millions of Americans with criminal records find work. Attorney General Eric Holder and other Democrats have spoken frequently about the issue, but so have conservatives such as Rand Paul and New Gingrich, who penned an op-ed in the Los Angeles Times supporting the California initiative.

One reason the issue has become so pressing is the large and growing number of Americans who have criminal records — and the evidence that many of those Americans are effectively shut out of the job market. According to one 2010 study, 12 million to 14 million people had felony convictions in 2008, about half of whom spent time in prison. The National Employment Law Project estimates that 70 million people — a quarter of U.S. adults — have an arrest history that can show up on a background check, whether or not they were convicted. Ex-offenders are disproportionately poor, less educated and black or Hispanic — groups that often struggle to find work even without criminal records. The slow economic recovery has made it even harder.

“There are still a lot of people looking for work, and if you have any issue that could create a problem, it makes it much less likely that you can get a foot in the door,” said Maurice Emsellem, an attorney at the National Employment Law Project.

Tuesday’s ballot measure is the latest in a wave of efforts, in California and around the country, to make it easier for Americans with criminal records to find work. In the past two years, eight states have passed “ban the box” laws prohibiting government agencies — and in some cases private employers — from asking about criminal convictions on job applications. Numerous counties and cities, including New York and Washington, D.C., have done the same. The laws aim to block employers from using criminal records as a blanket screen against hiring; employers can still ask about a candidate’s record, but not until later in the hiring process — at which point, at least in theory, prospective employees are more likely to be given a chance to explain themselves.

The federal government has also taken steps to stop employers from indiscriminately screening out candidates with criminal records. In 2012, the U.S. Equal Employment Opportunity Commission issued guidance saying that, because a disproportionate share of convicts are black, policies that rule out applicants based on criminal convictions can be discriminatory under certain circumstances — employers can’t just refuse to hire people with criminal records if their crimes aren’t relevant to the job they’re applying for. The Department of Labor has issued similar requirements for federal contractors.

The new policies come amid mounting concern from both politicians and researchers about the struggles of black and Latino Americans, particularly young men. The unemployment rate for black men age 20 to 24 was 25.1 percent in 2013, double the rate for white men the same age and more than triple that of the adult population as a whole. Those figures actually understate the racial disparity, because the government’s unemployment survey ignores people who are in prison and also likely undercounts blacks and Hispanics, especially men.

There’s wide agreement among economists that high rates of arrest and incarceration among minority groups are a significant factor in their economic struggles. But the impact is remarkably difficult to quantify for two reasons. First, causes and effects are difficult to disentangle: A criminal record makes it hard to get a job, for example, but the lack of good jobs also makes people more likely to turn to crime. Second, there’s a lack of good data. The government’s most comprehensive economic surveys — the Current Population Survey, the American Community Survey and the Survey of Income and Program Participation, among others — don’t ask about criminal background. The Bureau of Justice Statistics compiles data on prisoners but doesn’t track them after they are released. Various longitudinal surveys — most notably the National Longitudinal Survey of Youth — follow respondents over time, including after periods of incarceration, but their sample sizes are comparatively small and they often have other limitations.

In the absence of a single solid set of data, researchers are forced to triangulate, combining various sources and making assumptions where necessary to fill in the gaps.

“That’s the single biggest challenge,” said John Schmitt, an economist for the Center for Economic and Policy Research, a left-leaning think tank. “There’s no systematic data on people who have felony convictions or prison and jail records.”

Most of the research that has been done, however, suggests the effects of a felony conviction are large. One 2006 study, for example, found that young black or Hispanic men who had spent time in jail or prison worked eight fewer weeks a year on average than those who hadn’t been incarcerated. In a 2010 study, Schmitt and co-author Kris Warner estimated that in 2008, the low work rates among ex-offenders reduced U.S. employment by the equivalent of 1.5 to 1.7 million workers.

For people with criminal records, the difficulty finding work can persist for years, even though there’s little evidence that they are riskier employees. Research by Carnegie Mellon criminologist Alfred Blumstein has found that after about seven to 10 years, ex-convicts are no more likely to re-offend than the general population. But for employers worried about theft, workplace violence or other issues, there is little incentive to take a chance.

Esperanza Tervalon-Daumont, executive director of the Oakland community organization Oakland Rising, said that even with “ban the box” and similar rules, she doubts employers will ever become comfortable hiring ex-convicts. Proposition 47, she argued, could make more of a difference because it would actually reduce the number of people with felony convictions, not just change the rules for how companies treat them.

“Employment helps everyone,” Tervalon-Daumont said. “When these folks are given the opportunity to come back into the workforce in jobs … their relationship with the community shifts, so where they once were people who would be sort of a blight on the community they now have the opportunity to be a very specific kind of beacon.”