The capital was mobbed "on his say so"? What exactly did he say?
He said the election was being stolen, that Democracy was in jeopardy, that the mob needed to do something about it.
What did he say the mob should do?
Stop the steal, take their country back, fight like hell, be wild, march down to the capitol, stop the RINOs and Pence, the weak ones, etc etc
It was an hour's worth of inciting and an overload of incitement weeks and months leading up to the 1/6 rally of tweets, and ads, and rallies promoting the insurrection.
And then the President Sat back and watched gleefully on tv, and did not send help or speak against it for over 2 1/2 hours.