As much as the Obama administration would like to move past the IRS scandal, the ongoing work of the House Oversight and Government Reform Committee is making it impossible for the president to declare the story old news.

On July 19, 48-year IRS employee Carter Hull testified that the chief counsel’s office, which is headed by Obama appointee William Wilkins, was involved in targeting conservative groups seeking nonprofit status. As reported by The Wall Street Journal, Mr. Hull also stated that tea-party applications under his review were sent upstairs within the Washington office at the direction of Lois Lerner.

Mr. Hull was assigned in 2010 to tea-party applications, and even after receiving adequate information to determine whether to approve or deny nonprofit status to these groups, his recommendations often were dismissed. Instead, according to Michael Seto, the head of Mr. Hull’s unit, Ms. Lerner said those applications would receive additional scrutiny.

Last Monday, it was reported that visitor logs show Mr. Wilkins spent more than seven hours at the White House on April 23, 2012, not leaving until after 11 p.m. One day later, according to visitor logs, then-IRS Commissioner Douglas Shulman met with President Barack Obama. The timing of those visits could be significant, because Mr. Wilkins sent Ms. Lerner and Mr. Hull additional guidance for approving or denying tea party tax-exempt applications on April 25.

Ms. Lerner, as you might recall, invoked her Fifth Amendment rights when called before Congress earlier this year to testify about the scandal. Why she did so is becoming increasingly clear.

Today, it’s also obvious this scandal is not and never was the work of purported low-level officials at the IRS Cincinnati office, as the agency initially claimed. The latest testimony shows the targeting of conservative groups may have, in fact, been directed by Mr. Wilkins, the Obama appointee. If true, it would be much less coincidental that the extra scrutiny was carried out in an election year.

As we’ve learned over the years, congressional hearings are often a whole lot of show and very little go, no matter which party is in charge of them. But the conduct of the IRS clearly warranted an investigation, and that investigation is uncovering troubling information.

This scandal appears to be born from partisan politics. But regardless of whatever additional information the investigation turns up, Congress’ response shouldn’t be more partisan politics. Rather, the inquiry should spur bipartisan support for massive tax simplification and reform. Any system that gives unelected officials the ability to play partisan politics with Americans who follow the rule of law should be scrapped. It’s time to put an end to such motivations by taking the politics out of tax policy.