Critics of US President Donald Trump routinely accuse him of "gaslighting" - that is, of deliberately repeating misinformation to the extent that the public starts doubting verifiable facts and believing in his self-serving talking points.

On Sunday, a flurry of more than a dozen presidential tweets offered clear reminders of his tactics. In one glaring example, Mr Trump reiterated a lie that his political opponents are responsible for the forcible separation of the children of undocumented migrants arriving at the US border - it was his own administration that chose to pursue these measures, which have sparked a growing backlash.