What's the most damaging thing a lame duck president has ever done?

Doing a little research, it seems that most acts by lame duck presidents just involve political machinations.

There is an example of when an incoming president did do something that harmed the country and the lame duck president. But he didn’t do it to specifically harm the country. That was a byproduct of his decision and he went on to be one of the most respected presidents.

[Lame duck (politics) - Wikipedia]

We’ve had some bad presidents in these 256 years but I don’t believe that any of them were ever as hateful, spiteful and vain to believe that they should intentionally harm the country because they lost. Trump will be exceptional in that regard should he lose.