Trump appears to already be lying about his taxes. He claims that he can’t release them now because he is being audited. Whatever the mechanism, voters deserve a chance to assess Trump’s returns before they make their choice in November. The entertainer may be running a different sort of campaign, inspired by reality TV, but that doesn’t mean give him any leeway to cut them off from the normal information about a candidate’s private life.
Similar to Hillary's FBI indictment, it is unlikely that Donald Trump will lose his candidacy due to his practice of tax evasion. Perhaps Hillary's campaign will make sure everyone knows about it, but Trump has plenty of ammunition against Hillary to fire back with. So unless both candidates are to be removed, or a group of people are about to be very upset, it is unlikely that any of the candidates will be held accountable.
No, it won't. Everybody tries to lessen their taxes and if the means by which he did it is legal, he did no harm. Exploiting loopholes is not a crime. The average citizen may not like it or find it unsavory, but the laws are the laws. That is all.
No, Trump's tax evasion is not a concern for Trump supporters. They praise him for his shrewd business acumen, including his ability to rewrite the rules in his favor. They're looking for a leader who will aggressively renegotiate trade deals with other countries and assert American soverignty in the face of any international law that makes the U.S. less competitive. His willingness to flaunt U.S. tax law, already a sore spot for many anti-tax Trump voters, is therefore an asset, not a liability.