No benefit for a political candidate to say that.
In fact he should know history.
Juneteenth is when Republicans freed the last slaves that Democrats were holding.
Election day holiday would benefit future of USA much more than hashing over liberation of slaves. But the dumbing down of American has been a spectacular success, thanks to the teachers union and democrats and republican white guilt.
I became naturalized in 1970, I what happened during Lincoln presidency is as stupid as it gets for America’s future.