Donald has done it again, he has gone along and said something that is so beyond the pale that it is a wonder that the US electorate doesn't see red with rage.

And across twitter, this morning, the fury was there for all to see.

trump

This time, Trump was responding to the criticisms made by the father of a Muslim-American war hero, spoken at the Democratic National Convention. The father of Captain Humayun Khan said of the US presidential candidate that he hadn’t made any sacrifices for America. In a subsequent TV interview, Trump responded by saying that he made sacrifices by working hard and creating jobs (which was very unselfish of him) and then suggested that the mother of Captain Humayun Khan, who stood behind her husband as he made his criticism, didn’t speak because “maybe she wasn’t allowed to have anything to say,“ the inference being that she was forbidden from doing so as she was a Muslim.

With good reason, the twitter-sphere became ablaze with indignation.

The daughter of Senator McCain, himself a war hero who had been subjected to torture in a prisoner of war camp and ran against Obama eight years ago, entered the debate. Trump once said of McCain that he preferred it when war heroes didn’t get captured. Meghan McCain tweeted: “I would ask what kind of barbarian would attack the parents of a fallen soldier, but oh yeah, it’s the same person who attacks POWs.”

Other tweets home in on Trump’s writing, pointing to grammatical errors, while another pointed to three spelling mistakes in a Trump tweet.

But will it make a difference?

The US electorate doesn't usually take well to people who insult war heroes, or their parents, but there is this suspicion that anti-Trump indignation is simply going in a circle. Members of the anti-Trump brigade are tweeting each other; they preach (or tweet) to the converted.

And this is one of the problems with social media, it tends to amplify views you already hold. We saw it in the Brexit campaign, to a large extent people on either side of the divide tend to only look at social media that confirms their existing views. See Bias and the EU referendum.

As a rule, we tend to follow people on twitter who hold similar views to us, more so perhaps with Facebook. And in doing so, social media tends to reinforce existing views, it does not promote objectivity, it often promotes bias.

This was the warning made by Eli Pariser, author of the Filter Bubble. In 2011, Pariser told The Economist: “A world constructed from the familiar is a world in which there’s nothing to learn ... (since there is) invisible auto propaganda, indoctrinating us with our own ideas.”

You could say it is confirmation bias writ large. That is to say, we hold a certain view, we ignore all evidence that contradicts this view, only look at evidence that supports it, and become more convinced than ever that we are right. There is a danger that the internet, and social media in particular, can be a festering ground for confirmation bias.