As a nation we are far more tolerant than many countries within this world, we do tend to take a very parochial view of our country and many consider it the worst of worst, when actually, it's not bad.
Humans will always be wary of things that are unusual to us, that do not conform to our norms, but generally providing time is given (and this may be a long time), and there is give and take on both sides, assimmilation takes place.
Much as we imagine ourselves to be superior to all other animals on this planet there are very many similarities. You only have to watch a zoo program to see how difficult zoo keepers find introducing new members to an established group. We are no different.
Social media has enabled the pack mentality to show itself with one person posting bile and others feeling that they also then have lucense to post the same. Many would not say the things in face to face discussion.