CNN has a comprehensive rundown of the debate here.
So, why is this relevant to the monarchy? Well, this issue certainly speaks not only to Anglo-US relations, but to the unique role that the British monarch plays in the UK’s foreign diplomacy. It is noteworthy that a state visit in which a president is hosted by the Queen is considered so weighty and prestigious an honor that it is an effective tool to not only leverage but withhold as need be. The “dignity of the Queen” as the petition lays out is not in actual danger of being jeopardized by shaking hands with Trump – I’m not sure there’s anyone on this planet in a better position to bring him to heel than Queen Elizabeth – but it speaks to the role that she is being asked to play by the people. She is a reflection of their sentiments and values, and so to rescind the offer is, in theory, to say no to the ethos attributed to Trump thus far.
I’ve stated before that I think downgrading the visit is a mistake, however I also agree that offering the invitation in the first place, so soon into his term, was ridiculous. The government has already declined to cancel its plans and as of right now, a trip is believed to be in the works for this summer, possibly in Scotland to avoid protests in London.
Further background can be found here.