That’s the part I don’t understand.

He’s not in office, so he can’t delay any response.

Hell, if I were Biden, I’d have a plan ready with my cabinet (sec def, sec state, sec home sec), my joint Chiefs of staff, secret service, etc. Also have the governor of Maryland have his Nat Guard ready too.

Biden himself is safe at the White House. But I would imagine they will be more concerned securing the Capitol building.