Not only did Trump cheat on his taxes, he appointed a Secretary of the Treasury who swore he would never reveal Trump's tax returns. It now appears he also installed an IRS Commissioner who directed that no audits of Trump's taxes take place.
There are some of us who clearly remember that Tricky D!ck Nixon also cheated on his taxes, and refused to reveal his tax returns filed while he was in the White House. Nixon's tax returns were eventually leaked – revealing that he also paid very little taxes while claiming some highly doubtful deductions.
The written transcripts of many of Nixon's White House tape recordings had just been released, causing widespread revulsion to Nixon's foul language as well as his racial & religious prejudice. When his tax returns were revealed, the public reacted to this news with anger. Those two events, combined with the steady drum beat of Watergate investigations, added greatly to public accepting the idea that Nixon was a criminal.
Maybe the same will happen to Trump.