Barack Obama: “I am my brother's keeper, I am my sister's keeper.”

When we choose, when we make that decision, I do believe – and there is evidence for this – that the world gets incrementally better, and that is a worthy goal and it’s worth fighting for.

People need to “rediscover what’s the story we tell about how we’re going to live together, and see each other, and recognise each other, and disagree, and yet, still care for each other”.

And I will fight for that, even if I don’t always think it’s going to win.

The fact that any president, or any administration, is willing to engage in such transparent efforts to intimidate someone should outrage all Americans, regardless of how they feel about Congresswoman Omar’s political views.