> Due to previous years of underfunding, the IRS had cut back on the auditing of wealthy individuals and the shifting of assets among partnerships and companies became common.

https://www.propublica.org/article/how-the-irs-was-gutted

> The effects of an explosion in tax cheating would be dire. The nation’s already soaring budget deficit would surge by hundreds of billions of dollars more, pushing it well past $1 trillion. Commissioners of the IRS, starting with President George W. Bush’s appointee, Douglas Shulman, have warned Congress about a crisis like this since the budget cuts began, in 2011. But after eight years, Republican lawmakers, who are chiefly responsible for the reductions, show no signs that they think the danger is urgent. By the time the danger becomes indisputable, immense harm will already have been done.