Former presidents can be valuable to the incumbent government.
With their knowledge, experience and contacts, they have often acted in the past as advisers or envoys on diplomatic missions for ruling governments.
All of this is hard to imagine with Trump.
Here it will probably be the Biden government that breaks with this tradition.
"I think we have a better chance of getting a human to Mars in the next four years than that happens," says Updegrove.
The political ideas of Trump and Biden are too different.
Another courtesy that an incumbent government normally bestows on a former president is also hotly debated in the US: