Biden says that he is in for the race
With the announcement here, I reckon he should be the front-runner among the current Democratic candidates but it won't be a straightforward deal that he will win out to battle against Trump in 2020. To jolt your memory, Biden came close to running in 2016 but pulled out in the end, allowing for Hillary Clinton and Bernie Sanders to challenge.
This will also mark his third attempt for the top seat at the White House after having failed previously in two other attempts back in 1998 and 2008.