What did Donald Trump do today?

He came up with an interesting new justification for his border wall.

Trump, who was presumably preoccupied with the sentencing of his "fixer" and campaign finance co-conspirator Michael Cohen, took a leisurely approach to his office duties today, even by his standards. But he still found time to tweet out a novel suggestion about why Congress should fund his border wall.

Trump was apparently referring to a shooting in Strasbourg last night in which a gunman opened fire on a crowd at that city's Christmas Market, killing two and injuring 12 others. The shooter, who escaped the scene, is thought to be Chérif Chekatt, a lifelong criminal.

Taking Trump's tweet at face value, he seems to believe that "terror" in France would have been averted if that country had more "border security." 

Chekatt was born and raised in France.

Trump appears to have been trying to have the last word with "Chuck [Schumer] and Nancy [Pelosi]" after a photo opportunity with them on the subject of his border wall went disastrously wrong for him yesterday.

Why does this matter?

• It's really important that presidents sound coherent.