This is why we need to go to a no-loophole simple flat tax (with a generous initial earned income deduction to protect lower-income taxpayers). Getting rid of all those loopholes means the IRS can’t use its frightening power to intimidate anyone regardless of political affiliation.
The flat tax is still an income tax. As long as you have only wage income, it is easy to calculate. But, sell a used car, or boat, or gun, or have a garage sale or lemonade stand, and it is no longer so simple and you are no longer free from audit.
A business is never free from audit for income tax, as they always have expense deductions that can be questioned. Sales tax receipts can also be audited.
All the IRS has to do to get to a simple wage earner is to hint to their boss that the boss's IRS trouble will go away if the boss fires the wage earner.
Without a total change over in government personnel, there won't be a change in the harassment policy. Trump is the only one who might consider the necessary firings and jailings, but I doubt even he will do what is needed. As long as the IRS keeps hiring sociopaths and psychopaths, we are screwed.