As I write, Mr. Obama was recently on television condemning Mr. Trump for not paying taxes and claiming that Mr. Trump thinks taxpayers are suckers. A quick Google search suggests that other Democrats are making that claim, but Mr. Trump never said such a thing.
Isn't Mr. Trump bad enough, without having to make stuff up?
Mr. Obama is criticizing Mr. Trump for obeying the law, and wags his finger at Mr. Trump for not paying more than required.
Which is to say, Mr. Obama is making a moral issue over something that isn't wrong at all, and is something everyone tries to do: pay no more in taxes than is required.
Mr. Obama is like a toddler who tries to take another's toy and, when denied, cries "No fair!" He insults his own intelligence.
He's also like this restaurant manger. Don't be this guy. https://www.youtube.com/watch?v=KJtrLKGZZFg