Could the President of the United States get a second job while in office?

Moderators, I dispute this warning. Thread started in ATMB.

deleted - posted in wrong thread.

King of the Netherlands other job is part time as a pilot for KLM he flies 737s . He did it before he was king too. Nobody noticed he was doing the job until he did an interview about it. He says had he not been king he would have been a full time pilot. Like a lot of kings/queens now he does not really have any political power.

A revealing example is that marrying Elizabeth (and becoming “Duke of Edinburgh”) did not do wonders for Prince Philip’s naval career, and that he knew it, knew he could not do both, and made a choice.