While Mark Cuban has the perspective that Trump is greedy and should "do his duty" by paying taxes. Trump is smart for not having to pay taxes, as long the tax money he has saved comes from legal exemptions and deductions, that is the advantage of following the tax code correctly.
Trump is not smart, but greedy for not paying federal taxes. He intends to be the next President of the United States and commander in chief, yet does not think he has to pay for the defense budget like most Americans. He says he will increase funding for child care, but not by paying taxes. Instead, he intends to further increase the deficit and leave the bill for those very children he purports to help.
When Trump finds loopholes that allow him to not pay taxes in spite of the fact that he has more than enough personal financial resources, he is hoarding money for no better reason than to simply have it. This does not benefit his country or society in general. It reflects a greedy personality and ultimately hurts Trump by preventing his country and society as a whole from becoming all that it could be.
No, Trump is not smart for not paying taxes because it shows he does not care about anyone else but himself. He does not care about the welfare systems or the country's bridges. A smart person understands the importance of paying taxes. He has enough money to live a lavish lifestyle already.
The only proven requirement for winning an election is who has the most money to spend advertising. People are really that dumb and according to the National Science Foundation one in five Americans insists the sun revolves around the earth. However, by not paying taxes and being a sexist racist pig to boot doesn't exactly encourage a lot of people to donate money towards his election which is why he will lose.