Donald Trump cast a long shadow over the first Republican presidential primary debate on Wednesday night, as eight of his rivals sparred over his mounting legal woes while the former president skipped the event in favour of an interview on social media.

The live televised debate and Trump’s pretaped interview with former Fox News host Tucker Carlson on X, formerly Twitter, came a day before the former US president plans to surrender to authorities in Georgia, where he faces criminal charges relating to his efforts to overturn the 2020 election.

Trump’s rivals have been wary of directly attacking the former president, who remains the undisputed frontrunner in the crowded field. But the debate erupted when the topic of Trump’s behaviour was raised.