This is a surprise to no one
Joe Biden will end his protection of the world's worst secret when he announces his candidacy on Thursday, according to Bloomberg.
Biden is the favourite in the race. The latest poll of Democratic supporters put him at 27% compared to 20% for Bernie Sanders.
PredictIt has Biden as a slight favourite over Sanders followed by Buttigieg and Harris.
It's way too early for predictions but my guess is that a better US economy than anticipated a few months ago gives Biden the upper hand because Democratic voters will be more nervous about Trump winning and less willing to take a risk on Biden. But who knows.
Polls on Sanders vs Trump and Biden vs Trump put both ahead of the President but sanders is +2.7 pp while Biden is +7.7 pp, according to RealClearPolitics.