It's also a major flash point in an epic he-said, she-said battle Congress is in the middle of concerning the IRS. It's not unlike the ones you had in elementary school -- except this one has lasted years, cost Americans millions of dollars and comes to no bipartisan conclusion about what happened.
At its heart is whether, in the fallout of the 2013 IRS scandal, the man who came in to clean things up has really done so. As you can probably guess, what you think about Koskinen's job performance depends on your politics.
Republicans on the House Oversight and Government Reform Committee say a series of mysteriously destroyed and/or unsearched hard drives of a key IRS witness suggests a nefarious coverup. They are also moving to try to impeach the head of the IRS for all this, although that's a bit more of a long shot: The last Cabinet-level office holder or agency head to be impeached was William Belknap, the secretary of war, in 1876. Plus, not all House Republicans are even on board with the idea of a censure.
Meanwhile, House Democrats think Republicans are taking out all their anger about the IRS on one noble public servant, a man who came out of retirement to lead the embattled agency, no less. Plus, independent investigators found no evidence of wrongdoing.
Clearly, there's not a ton of nuance when it comes to this seemingly never-ending IRS drama. Let's go a little deeper on both sides' reasoning:
First, what everyone agrees on:
If we go back a few years, there is one fact both sides agree on: that for a time, IRS agents singled out conservative groups to review for extra scrutiny. When news of the practice broke in 2013, President Obama said, "It's inexcusable, and America has a right to be angry about it."
But that's where agreement ends. Republicans still think there's good reason to suspect that the IRS did it for political reasons. We should also note the IRS is not a popular agency among many conservative voters: Sen. Ted Cruz (R-Texas) promised during his presidential campaign to get rid of it. Democrats say several investigations -- at the IRS and in Congress -- found no evidence of that. Obama later said there's "not even a smidgen of corruption."
In a statement Wednesday after the vote, Treasury Secretary Jack Lew defended Koskinen as "an outstanding public servant of the highest integrity" who has cooperated with Congress and accused Congress, of which he was a member, of pursuing a "political agenda" in trying to get rid of him.
What Republicans say:
When viewed through their eyes, what happened at the IRS next looks suspiciously like a coverup from the highest levels: The IRS employee at the center of this -- Lois Lerner, then the director of the IRS's exempt organizations unit -- invoked her Fifth Amendment right not to testify when called before Congress. Obama made his "no corruption" comment while multiple investigations were still underway.
Koskinen, who came out of retirement to lead the troubled agency, promised to find all of Lerner's emails and cooperate with Congress. And then 422 backup tapes that might contain those emails were erased.
What's more, the IRS's inspector general -- the independent watchdog tasked with looking into all these allegations -- ended up finding copies of more Lerner-related tapes where IRS officials said there were none.
None of the evidence recovered has a smoking gun Republicans are looking for. But for Republicans, the outrage comes more from what they don't know than what they do know.
"If those tapes had been properly preserved," reads the narrator on a video Republicans put together to explain all this, "an additional 24,000 emails might have been recovered, and maybe there would be answers."
Rep. Jason Chaffetz (R-Utah), chairman of the oversight panel, indicated that there's a double standard here, too.
"I'd be fascinated to know," he told Democrats protesting the censure vote Wednesday, "if there were a different person in the White House, how you all would feel if certain groups you thought were worthy were being targeted."
What Democrats say:
Republicans are trying to connect dots that just aren't there.
They're making something out of a series of events that really amounted to bad luck for the IRS: With Congress's eyes on it, two low-level employees erased those backup tapes containing Lerner's emails so the tapes could be reused. These employees working in a data center for the IRS in West Virginia simply missed the memo from the top to preserve everything.
Democrats add that that's not their conclusion, but the conclusion from the IRS's inspector general, Russell George, who was appointed by President George W. Bush.
"When did we as a committee become so God-like that we can say that a person is lying?" Rep. Brenda Lawrence (D-Mich.) asked Wednesday.
Democrats also point out that when George looked at the broader question of whether the IRS targeted conservative groups for political reasons, he found no evidence.
So if all the evidence points to no evidence of wrongdoing, Democrats argue, why ruin a public servant's life by voting to censure him?
"I really believe we're going too far," Stacey Plaskett (D-Virgin Islands) said Wednesday before the vote.
A little more about the censure:
The issue isn't just dividing Democrats and Republicans. There appears to be a split between hard-line conservatives, who want Koskinen gone, and the rest of the House Republicans, who don't seem too eager to take that step.
Originally, Chaffetz wanted to impeach Koskinen -- a much more serious charge than censuring him. But there didn't seem to be a lot of support for that, even among his fellow Republicans.
House Speaker Paul D. Ryan (R-Wis.) stopped short of supporting even the censure when The Washington Post's Lisa Rein and Mike DeBonis asked him about it in April.
"What I think we need to do is win an election … get better people in these agencies and reform the tax code so we’re not harassing the average taxpayer with a tax code they can’t even understand," Ryan said.
Given that, it's entirely possible that Wednesday's vote is as far as this IRS fallout is going to go.