Clearly, IRS examiners investigated whether applicants should have been given tax exempt status to spend less than half their time and money making political ads. Some asked who were members of the group, which seems illegal, because if they did that, they'd see that the same names popped up in several of the other applications.
As the 'buck stops at the President, he should be impeached.
If a janitor (sanitary engineer) in a National Park rest room steals a box of toilet paper to take home, that is illegal. That act alone should make the President impeached, as he's ultimately responsible for all 288,000 federal employee actions.
As he's in complete dictatorial control of all the nation, they couldn't possibly misbehave without his knowing about it. Every department head is afraid his head will roll if there is misbehavior. So he is at the same time a President who has no control of all the personnel, and he's a complete dictator, depending upon the date of GOP media publications.