What did Donald Trump do today?

He gave himself a massive tax cut over and above the one he already signed into law.

Today, Trump's Treasury Department issued regulations defining how certain business structures known as "pass-through entities" will be affected by last year's tax bill. While unfamiliar to most Americans, pass-through entities were already a common tax shelter for a small subset of wealthy business owners. 

Now, the tax benefits will be much higher--but only to businesses that meet certain standards. Trump's regulations are written in a way that will greatly increase the portion of Trump's own businesses that will qualify for the lower rate. 

For example, the Trump Organization, which includes hundreds of pass-through entities, wouldn't qualify for much based on the plain text of the law. For example, businesses that sell the "reputation" of their owner don't get the break. Although he presents himself as a real estate tycoon and hotelier--industries where he went bankrupt six times--most of Trump's wealth now comes from licensing his name and image. Trump receives royalties on everything from hotels he doesn't own to vodka he doesn't drink. 

But the regulations define "reputation" very narrowly, and would allow Trump to pick and choose what parts of his business income qualified. More typical businesses, which earn their income in specific ways, would not have that option.

Trump adamantly refused to put his business interests in a blind trust when he took office, which would have prevented him from writing tax regulations that specifically benefited him.

What is the problem with this?

• It's wrong to use your government office to make money for yourself.

• Presidents who won't avoid conflicts of interest have already decided to put their own interests ahead of the country's.