Labour movements on both sides of the Atlantic have a rich history that's worth rereading now.
Thanks to the US's polarised politics, presidents beloved abroad are controversial at home.
There's no middle ground when it comes to a president like this.
The ties between the US and UK have long been depicted in loving terms. But with these two in charge, it can only be a marriage of convenience from now on.
It's all smiles as two leaders meet for the first time, but it'll take more than warm words to navigate the choppy waters ahead.