The New York Post wants you to know that someone who was once arrested for drug possession in 2013 got a new job in 2015.

That doesn't seem newsworthy on its face (at least, it shouldn't). But because the job in question is a top communications job on Hillary Clinton's presidential campaign, the Post appears to think it's important.

Zac Petkanas was hired by the Clinton campaign a few days ago to run its "rapid response" communications team. In 2013 (according to the Post), while working for the Nevada Democratic Party, he was admitted to a New Orleans hospital — and when the nurse discovered Petkanas had methamphetamine in his pocket, he was arrested in the hospital for drug possession. Petkanas agreed to do a pretrial diversion program, and the charges were dropped; he also, voluntarily, went into rehab.

The Post doesn't offer any explanation for why Petkanas's 2013 arrest for methamphetamine possession would make it harder for him to do his job in 2015. And it doesn't explain why his hire should be embarrassing to the Clinton campaign. The campaign doesn't appear to have tried to hide Petkanas's arrest from the public. To the contrary, a spokesperson told the Post that the incident "was a bad choice" but that Petkanas "has made a full recovery in the years since. We are very glad to have him on our team." And while there's a legitimate argument to be made that a political staffer's personal behavior matters when that behavior is at odds with the policies he's pushing, what happened to Petkanas is consistent with the public health approach that Clinton and other Democrats and criminal justice reformers are beginning to take to drug policy. The Post doesn't even bother to make a case that Petkanas or the Clinton campaign is being hypocritical.

What's left is the insinuation that ever having been arrested for drugs is a Bad Thing, and that campaigns (or, by extension, anyone else) shouldn't hire people who have done this Bad Thing. Ironically — but worrisomely — this comes right after both New York City and the federal government have made moves to reduce discrimination in employment against people with criminal records. Articles like the Post's make it clear that a stigma still exists against people with criminal involvement in their pasts.

Hiring someone with a criminal record isn't a bad thing

About one in four American adults has a criminal record. (The number could be higher.) That's a large portion of the potential labor pool for any job — and, of course, an even bigger portion of the pool for low-wage jobs in particular.

It's extremely common for employers to discriminate against job applicants with criminal records, especially if those job applicants aren't white. But being unable to get a job after a run-in with the law makes it extremely hard for someone to stay away from criminal activity in the future.

That dilemma is behind the recent push to "ban the box," prohibiting employers from asking about criminal histories on job applications. On Monday, President Obama announced he was directing the federal government to delay asking applicants about criminal histories until later in the hiring process whenever possible. And at the end of October, a "ban the box" law that prohibited any employer (public or private) from asking about past convictions on applications or during interviews went into effect in New York City — where both Hillary Clinton's 2016 presidential campaign headquarters and the New York Post are located.

The idea behind ban-the-box laws is that if an applicant has the chance to impress a potential employer as an individual, the employer won't stereotype him as a "criminal" even after finding out about his record. But if the stigma against hiring someone who's committed a crime is too strong, the impression the applicant's already made won't matter — the employer will disqualify him at whatever point in the hiring process the criminal record happens to come up. Ban the box is a good example of a general principle: Laws can't eradicate social stigma; at best, they can work around it. Eradicating stigma completely is measured in changes to the way people interact with one another when they're not being told what to do.

When the media treats a past drug arrest as a big, bad deal, that's a pretty powerful reinforcement of stigma against people with past arrests. It confirms the fears and suspicions that employers — and customers, and everyone else — might have: You are right to be worried about these people; society agrees they're untrustworthy and should be avoided.

It's easy to defend discrimination against someone when not discriminating would get you in trouble

This sort of thinking is especially dangerous when it gives people an out to defend discrimination on the basis of what other people will think or do: It's not what I think, it's what the family/community/customers/society thinks. Employers don't want to bring trouble on themselves simply by hiring one person over another; why would they? On a case-by-case basis, it's a commonsense decision; collectively, it's how stigma works.

For a presidential campaign, getting in the paper for making a risky hire is a kind of press that the campaign doesn't want at all, and typically does its best to avoid. This is why high-profile hires are so thoroughly vetted. The Clinton campaign could have decided that hiring Petkanas wasn't worth the risk of this getting out; plenty of campaigns have made decisions like that plenty of times. Instead, they decided Petkanas was worth the risk of publicity — and the Post, helpfully, immediately reminded them why campaigns so frequently discriminate.

Most employers don't get the same level of public scrutiny that presidential campaigns do; I'm not saying that a hardware store owner needs to worry about his name turning up in the New York Post. But all employers have to worry about the public in some regard. And that's why many employers use background checks to begin with.

Background checks are rarely a test of the applicant's moral character: In a 2012 Society for Human Resource Management survey, only 17 percent of employers who used background checks said that "assessing the overall trustworthiness of the job candidate" was a primary reason. Instead, they're worried that hiring someone with a criminal record will create trouble with them for other people. Fifty-two percent of employers who conducted background checks said their primary concern was to reduce their legal liability: If an employee did something wrong to a customer or simply made the customer uncomfortable, the employer didn't want to get sued for "negligently" hiring someone she could have known was a threat.

How often that actually happens, and how justified employers' fears might be, isn't particularly relevant. It's something that employers feel exists, and it's much easier for them to protect the public from ex-offenders than for them to get the public to stop seeing ex-offenders as constant threats. It's a powerful argument for an employer not to try to be a hero, and to acquiesce to a social norm even if she believes it's wrong.