Republican hopefuls battle it out in California, hoping to put a dent in campaign of frontrunner former president; he heads to Michigan instead

Even without being there, former US president expected to dominate dialogue, as others wrangle for attention while trying to avoid any missteps

Former president claims Americans know him well so there's no need for a public showdown with his rivals for the White House

Emerging spat a preview of potential tension that could lie ahead as ex-US president aims to establish himself as undisputed nominee; he skipped several debates in 2016 runup

While then-US president tested negative soon after positive test, got all-clear from doctor, he wound up getting so sick days later that he had to be hospitalized, memoir recalls

Debate commission hopes 'candidates will be respectful of each other's time'; Trump campaign incensed by decison, but says president will participate

The two presidential candidates will battle for airtime after the US president refused to hold a virtual debate in wake of his COVID diagnosis

US president rejects committee's announcement that the candidates will debate from 'separate remote locations' due to his COVID-19 diagnosis; Biden campaign says he'll participate

Despite still being contagious with coronavirus, US president insists he intends to face off with Joe Biden in second round next week as planned

After days of appearing to equivocate on the matter, US leader says 'let me be clear, I condemn the KKK, I condemn white supremacists. I condemn Proud Boys'