No, ignorance of the US, the superpower with the most relevance to life and politics in the wes, is the result of deficiencies in the education of a great many posters, combined with a large dollop of xenophobia.
It surely must be plain at this point that there are very few Brits who appreciate the issues around Brexit, since it was approved in the referendum and the party that presided over that referendum has been in power ever since and there is still nonsign that anyone in it understands its repercussions.
Jeremy Corbyn was pushed aside because the howling of the gutter press turned him into a political pariah. Where is Corbyn now? Outer Mongolia. There was a point in recent British political affairs where all the Tories had to do in any debate on any topic was say, "But Corbyn!" End of discussion. Such is the power of the tabloids. And Labour has no coherent policy when it comes to Brexit either.
British politics is manipulated by the intensely political and powerful tabloid press, to an extent that is shocking to the rest of Europe and the US. It's populism in action, to the Nth degree. Hence Boris Johnson, journo turned politician turned journo, with the only constant in his career being the correct instinct that cultivating a persona and becoming a 'character', even down to his choice of hairstyle, was the way to the top.
The picture you're trying to paint of an American electorate and American people and culture in general is part of a compare and contrast exercise designed to present Britain as moderate and sensible and progressive. I don't think there are many left of centre voters in the UK who would share this view.
You should be aware that the thoughtful American press offers regular coverage and analysis of British politics and economics, aimed at a readership that is correctly assumed to understand a great deal of the background.