We must start urgently talking about the dangers of a second Trump presidency | Margaret Sullivan

With New Hampshire behind, the question isn't who's running but whether US democracy will endure

With Trump's victory in New Hampshire, the battle lines are drawn for November. Unless something very weird happens, we're looking at a Joe Biden and Donald Trump rematch.

It's time - past time, really - to sweep away any remaining delusions about the viability of a more moderate Republican challenger or what a second Trump term would bring.

Margaret Sullivan is a Guardian US columnist writing on media, politics and culture