Donald Trump lost Wisconsin, but he got his message out through the media. (Nancy Wiechec/Reuters)

Donald Trump lost badly to Ted Cruz in Wisconsin’s Republican presidential primary Tuesday, but many news outlets awarded a consolation prize by spreading the front-runner’s unfounded accusation that Cruz cheated his way to victory by breaking the law.

Without offering any proof, the Trump campaign said in a statement that Cruz “was coordinating with his own Super PACs (which is illegal), who totally control him.”

It’s no surprise that Trump would take this route. He charged that Cruz stole a win in Iowa (he didn’t) and more recently blamed the Texas senator for a super PAC ad that featured a racy photo of Trump’s wife, Melania. There is no evidence that Cruz was responsible for the ad, just like there is no evidence that he illegally coordinated with any super PAC in Wisconsin.

But instead of contextualizing Trump’s latest wild claim as being part of a pattern, NBC News, Fox News, the New York Times, the Los Angeles Times and others simply published it uncritically without noting the lack of support for the billionaire’s assertion. The Associated Press included an unfiltered version of the statement in its stream of primary-night updates.

How Ted Cruz won the Wisconsin GOP primary, in 60 seconds (Peter Stevenson/The Washington Post)

I should note that some or all of these outlets might have challenged Trump in subsequent articles or broadcasts, or refused to repeat his accusation again. I don’t claim to have read and watched every word/second of coverage. I do know that The Post and the Times, for example, did not include Trump’s charge of illegal coordination in the lead stories that ran in their respective print editions on Wednesday.

Regardless, the press largely gave Trump exactly what he wanted — at least initially. He wanted to delegitimize Cruz’s win while casting aspersions on his rival’s integrity, and the media allowed him to do it.

A few outlets pushed back right away. The Blaze, the conservative news site founded by Cruz backer Glenn Beck, published Trump’s statement but added that “no evidence was given ... to support the serious allegation.” The Houston Chronicle, in Cruz’s home state, posited that “Trump’s accusation of illegal coordination was a reference to Cruz’s participation in campaign events organized by Keep the Promise, a putatively independent Super PAC that supports Cruz.”

Indeed, Cruz made appearances at three Wisconsin events organized by Keep the Promise in the days before primary voting. But even the Chronicle story did not make clear that such appearances are permitted by the Federal Election Commission. They are not considered coordination.

One of the problems, as Trump surely knows, is that rules governing coordination between a candidate’s official campaign organization and ostensibly independent super PACs are famously hazy — making complaints about supposed violations difficult to fact-check. But it is absolutely untrue that campaigns and super PACs are required to maintain total separation, as The Post’s Matea Gold explained in a story last summer, early in the race.

Under Federal Election Commission rules, there is no wall dividing candidates and independent groups. In practice, it’s more like a one-way mirror — with a telephone on each side for occasional calls.

“The rules of affiliation are just about as porous as they can be, and it amounts to a joke that there’s no coordination between these individual super PACs and the candidates,” said Rep. David E. Price (D-N.C.), who has sponsored legislation that would put stricter limits in place.

A close reading of FEC regulations reveals that campaigns can do more than just publicly signal their needs to independent groups, a practice that flourished in the 2014 midterms.

Operatives on both sides can talk to one another directly, as long as they do not discuss candidate strategy. According to an FEC rule, an independent group also can confer with a campaign until this fall about “issue ads” featuring a candidate. Some election-law lawyers think that a super PAC could share its entire paid media plan, as long as the candidate’s team does not respond.

It’s unreasonable to expect every story to include so much background, especially on deadline on primary night. But it’s not too much to ask for journalists to point out that Trump has no evidence to back up a very serious claim, that he has a history of crying foul when things don’t go his way, and that the relationship between Cruz and his super PAC that has been documented is perfectly legal.

Trump’s campaign thrives on dubious information. The media shouldn’t help him spread it.