President Trump needs a win. The public would benefit from reassurance about the institutions of government. Luckily, both can be achieved with a single action. Trump should dismiss IRS Commissioner John Koskinen.

By telling the taxman he's fired, the president would re-energize his young administration. More importantly, he would also significantly reform the most loathed agency in Washington. Tax Day provides a perfect chance for this sort of principled populism.

This Tuesday the tax man cometh. Members of the public will dutifully cut the IRS a check. No sane person enjoys this April ritual, but most people understand they should pay their fair share. It's one of the costs of civil society. But as we drop a check in the mail, we should know that the IRS is playing by the rules.

So long as Koskinen stays in his job, taxpayers have no such assurance. He was brought in by President Obama to clean up the IRS in 2013, but has succeeded only in making the agency more corrupt. A political crook and a liar, Koskinen has no place working in the Trump administration.

While it seems like ancient history and still defies the imagination, the IRS systematically harassed and bullied conservatives because of their political opinions. Ahead of the 2012 election, tax agents deliberately slowed the applications of Tea Party organizations seeking tax-exempt status, forcing them to unmask members, reveal donors, and describe activities. Members of one group, the Iowa Coalition for Life, were even asked to detail the contents of their prayers.

Koskinen wasn't calling the shots then, but he hid the full extent of the scandal. First, he obstructed a congressional investigation by allowing tens of thousands of subpoenaed emails to be destroyed. Then over four months, he lied to lawmakers about where that evidence was.

Taxpayers cannot hem and haw as Koskinen did. When the taxman comes knocking, citizens can't destroy records or forget receipts. That sort of behavior would trigger an audit, or worse, lead to jail time. And normally a federal official wouldn't be able to get away with this type of activity. It'd be damning.

But Koskinen set himself above the rules. Trump vows to drain the swamp, and the IRS boss is an especially capable and devious swamp monster. House Republicans have tried shaming, censuring, and even threatening to impeach him. But each time, he's found a way to survive.

The failure of past lawmakers provides Trump a perfect opportunity. As the head of an administrative agency, Koskinen serves at the pleasure of the president. A word from Trump would send him packing and bring closure to the controversy.

A principled power move, firing Koskinen would also provide the White House with a needed influx of political capital. What's more, it would signal the beginning of a new era of good government during the Trump era.