A very real possibility, which I already see as being a 50/50 chance. I think outside the USA we have to steel ourselves for a Trump II presidency. Inside the USA? I think every decent human being needs to become a political activist right now, and do whatever they can to combat the lies and voter suppression, to begin with.
Having Biden as candidate hardly makes it an easy or even palatable task, but the risk of Trump winning again is just too great.
Ukraine handed on a plate to Putin, absurd trade wars with China causing another global recession... not to mention the dismantling of decades of equality and rights progress domestically.