Dutch citizen here, but just to drop my two (euro-) cents.
What JMS meant was meant literally. Not figuratively. The shot of Johnson’s inauguration is pretty well known in the USA. By copying the staging JMS tried to pull some emotional strings. It likely would have gone over the heads of most foreign viewers, but for those that lived through the JFK shooting it might work.
Just compare these photos of Johnson’s inauguration and Clark’s inauguration.
https://en.wikipedia.org/wiki/First_...ember_1963.jpg
https://i.stack.imgur.com/stsYO.jpg