Where did he clearly incite an illegal action? As far as I can tell his speech just told his supporters to walk to the Capitol. He didn't say anything about committing illegal acts. In fact, he explicitly said people should be peaceful. Courts are not going to try and parse secret messages from a speech when there is an explicit disavowal of any criminal act.
The rule people seem to be advocating for here is that if a politician directs their supporters to protest at a particular location then they are responsible for all illegal acts their supporters carry out at that location. That seems to be unreasonable standard and it is also a standard that legally has not been applied before. In terms of politics/media I'm sure people have tried to apply this standard but it is very wrong. It seems every time some whacko commits a crime one side will accuse the other side of inciting the crime with their rhetoric. I don't think this is at all fair and I also believe it could lead to an equilibrium where people are incentivised to commit crimes. It is often quite hard to murder a politician (ask the baseball shooter) but if you can take a piece of the board by committing a crime and getting caught then that might be better option for a whacko. Obviously, this has not happened in this case but if this standard is enforced then this is something to worry about in the future.
The rule people seem to be advocating for here is that if a politician directs their supporters to protest at a particular location then they are responsible for all illegal acts their supporters carry out at that location. That seems to be unreasonable standard and it is also a standard that legally has not been applied before. In terms of politics/media I'm sure people have tried to apply this standard but it is very wrong. It seems every time some whacko commits a crime one side will accuse the other side of inciting the crime with their rhetoric. I don't think this is at all fair and I also believe it could lead to an equilibrium where people are incentivised to commit crimes. It is often quite hard to murder a politician (ask the baseball shooter) but if you can take a piece of the board by committing a crime and getting caught then that might be better option for a whacko. Obviously, this has not happened in this case but if this standard is enforced then this is something to worry about in the future.