Sign the petition to support Trump's visit.
https://petition.parliament.uk/petitions/178844
Where were the protests and petitions when Robert Mugabe had a state visit? And what about China? They have Human Rights abuses going back into history. There was a small protest but nothing on this scale.
We export more stuff to the US than to any other country. While that doesn't mean we should put up with any crap from the US, it does mean that we should think long and hard before we let a minority of people sour any kind of relationship with the US. Trump will not be president forevever, we should keep ourselves in a position to have a word when we don't agree with something instead of alienating ourselves completely ourselves.