Well, it begins

Biden will be named the nominee. He has $100 million campaign funds. They can only go to whoever replaces the nominee.
If he steps down before the naming of a nominee, it becomes an open convention. If he gets replaced after receive nomination, top DNC brass choose whoever they want. That person gets Joe’s $100 million.

And the Dems claim Republicans are destroying democracy. The Dem primary voters are being disenfranchised.

And won't listen to reason.
Or in other words they're too dumb, obstinate, obtuse, etc etc etc

Odds makers -- U.K. or U.S.-- are the most practical minded and realistic people on Earth. They can't afford to be partisan. It's all about the bucks with them.