President Trump is running headlong into the very ethical minefields that we warned of when we encouraged him to sell his hotel empire. The new problems were predictable, will be persistent and could tarnish his presidency.

Trump Hotels' CEO announced plans this week for vast expansion of hotels in this country. "There are 26 major metropolitan areas in the U.S., and we're in five," CEO Eric Danziger told reporters this week. "I don't see any reason that we couldn't be in all of them eventually."

Denver, Seattle, Dallas and San Francisco are the cities Danzinger named. That's just the luxury hotels. The moderately priced Trump hotels, to be called "Scion" hotels, will start opening this year and will spread beyond the major cities.

The conflicts are many.

Trump still owns the company, despite repeated calls from Right, Left, and center (including this page) to divest. So the company's ability to expand over the next four or eight years determines how wealthy Trump will be when he emerges from the White House and, as he has suggested, retakes the helm of the company.

Will Trump, in his presidential travel, favor cities where new hotels bear his name? Will his massive infrastructure plans favor roads or transit around his new hotels? Given his penchant for scattershot subsidies and taxes (see Carrier, for instance) will he help the business partners of his new hotels, or hurt the rivals in some way?

What if a mayor or governor, for reasons valid or political, derails the plan for some new hotel? Would Trump punish an American state in the same way he's pledging to punish Mexico now? With resources at his fingertips, such as the Army Corps of Engineers, the Environmental Protection Agency, the Internal Revenue Service, the Bureau of Land Management and a thousand other agencies, the president could make San Francisco pay for any disruption of a new Trump Tower.

Even if Trump somehow sets aside the interest of the company he still owns, and instead governs only in the interest of the nation, there are risks.

First, there's the threat that subordinates in any of these agencies will be afraid to do the right thing if it would hurt the president's businesses.

Second, there's the appearance of impropriety. The more his empire spreads, the easier it is for a critic to see some way businessman Trump benefits from President Trump's decision.

The appearance of impropriety is already nagging Trump internationally, where he has sworn off any new deals, but is keeping his existing hotels. Critics have noted a coincidence: The list of Middle East countries with residents he wants to bar from entry to the U.S. omits Egypt, Saudi Arabia, Turkey and United Arab Emirates. Those happen to be the five Middle Eastern countries where he has hotels.

Saudi Arabia is a notable exception from the visa list because 15 of the 19 Sept. 11 hijackers came from there. The other four came from Egypt and the UAE. One of the two San Bernardino shooters travelled from Saudi Arabia.

So an immigration ban in the name of counter-terrorism that excludes Saudi Arabia, Egypt and the UAE appears dubious, and immediately conjures the thought that these countries are exempted for extraneous reasons.

These messes will not go away. The law doesn't require Trump to sell his hotel business. Good government and basic ethics do.

The question is whether Trump grasps the importance and difficulty of this job and sees himself as a public servant, or if he still see himself as a hotelier, who now has a side job on Pennsylvania Avenue.