Like it's not already? You're killing me Smalls!
For regular income it is, but for its own purposes, not the rest of the government's. Of course, Lerner's abuse, with Obama WH collusion, was aimed at restricting access to charitable status. And, its said Clinton used audit power to hassle those he disliked. But flat out sharing of tax filings and audit info with the government was at least somewhat protected. That's why going after Trump's info is such a step down.
One of the "horrible" things Nixon was accused of was asking if he could use the IRS to hassle his opponents. Asking, not doing. But, that was then, and this is now.