If you’re resigning from your newspaper job after twenty years, here’s a hell of a lede: “I’ve worked for almost two decades at the Chicago Sun-Times because it had a soul.”

Dave McKinney resigned from the paper this week after the paper chose to endorse a candidate he’d been covering. McKinney was co-authoring a piece on Bruce Rauner‘s company LeapSource and its fired female CEO, in a vetted piece “on litigation involving the former executive, who alleged Bruce Rauner, while a director of the company, threatened her, her family and her future job prospects.”

Someone from the Rauner campaign wrote to McKinney’s boss claiming that McKinney could not report the story because his wife was involved with a PAC working against Rauner. McKinney’s reporting was pulled from other stories and he was put on leave. When he returned to the office, he was discouraged from reporting further.

Here’s the paper’s main problem with the article: Michael Ferro, the person McKinney’s addressing in this letter, bought the Chicago Sun-Times in 2011 with an investor group that included Rauner. Rauner’s campaign could have power to influence high-level executives at the paper; they decided to push back because of who McKinney married. (He had filed with the paper in advance about his wife’s political position, and was approved before he began work on the story.)

“One of the reporters had an extraordinary conflict of interest — married to a Democrat operative with deep connections to the major group attacking Bruce Rauner,” Chip Englander, Rauner’s campaign manager, told the Chicago Tribune last Friday.

McKinney said that the staff of the campaign threatened to “go over” the heads of his editors. No wonder he chose to walk. Here’s more from his report:

The Sun-Times is stocked with dedicated reporters, editors and columnists, who work every day with integrity, long hours and not enough pay. They are more than colleagues. They are my friends. They are my family. They are the soul of the Sun-Times.

But today, I’m faced with a difficult decision due to the disturbing developments I’ve experienced in the last two weeks that cannot be reconciled with this newspaper’s storied commitment to journalism.

In the time between the reporting and McKinney’s leave, the Sun-Times reversed its policy of abstaining from political endorsements in order to endorse Rauner. McKinney’s final paragraphs are a marvel:

Readers of the Sun-Times need to be able to trust the paper. They need to know a wall exists between  owners and the newsroom to preserve the integrity of what is published. A breach in that wall exists at the Sun-Times.

It’s had a chilling effect in the newsroom. While I don’t speak for my colleagues, I’m aware that many share my concern. I’m convinced this newspaper no longer has the backs of reporters like me.

…We reporters have a healthy suspicion of both parties and candidates. It’s our job. It’s regrettable that this issue has emerged in the homestretch of an important election in Illinois, but respectfully, this isn’t about either candidate or the election. It’s about readers and their trust in us. So my decision could not wait. I hate to leave, but I must.

And so, it is with great sadness today that I tender my immediate resignation from the Sun-Times.

We’ve covered other changes at the Sun-Times here, beginning with their cuts to the books section, and their photographers. Failing to stand behind a staffer after twenty years is another big loss for this company.