The demonstartions are nothing to do with the D Day celebrations, other than the fact that Trump is currently President of the United States and they played a major part in the war.
Protesting against Trump does not therefore affect our respect for all those who served and those who died in World War 2. What brings disgrace is that the current holder of the post of President of the US is a man of limited intelligence, who works with his countries enemies and is a serial fantasist. I have no illusions about the character of previous Presidents, but this one is a draft dodger who dared to criticise the military record of one of the US's greatest and well deserved military heros, John McCain.