I think something relevant here is that the White House Counsel seems to have been telling everyone that they would be committing crimes by helping Trump go to the Capitol (“we’re going to get charged with every crime imaginable if we make that movement happen”). If that was correct, they weren’t allowed to drive Trump there.
Maybe at some point the agents would separate along party lines and have to shoot it out. But I may be swayed by my like of Tarantino movies.
While they are sworn to protect the President’s life, they do not carry out policy or political actions. If a president wanted to stop and run into a burning building or attempt to catch a suicide jumper, they would stop him. Essentially protect the office of the president. There is no requirement to get him/her to a political address or action in the face of danger.
They don’t?
Supposed to. Perfect world. Android agents.
Apple is pissed.
Nicely done. That’s a good one. 
I believe the issue is ‘did the SS engage physically with the POTUS’. Not just in the sense of carrying him out of danger, but restraining him to countermand a direct order. The Pres said go to the Capitol and SS advised ‘no’. The President made it clear that he intended to go to the Capitol. It was not a casual request. The Pres reached for the steering wheel and the SS grabbed his shoulder/arm restraining him as they drove away. The SS physically interfered to prevent the President of the US carrying out an act of political policy. Their job was to protect him during the act, not make a judgement to prevent it.
It is understandable that the SS does not want this debated in public. I wouldn’t want their job at any price.