A. The dynamic between Biden and Warren will be particularly interesting, given not just their proximity in polls but the fact they embody the philosophical divide in the race, between the relative centrism of the former vice president and the leftward leaning of Warren.
The two have a long, somewhat adversarial history, and if they chose not to engage, you can be pretty certain the debate moderators will seek to draw out their distinctions on healthcare and a past run-in over regulating the credit card industry, among other differences.
Q. Any other subplots?
A. Harris was the standout on June's debate stage and was widely panned for her performance in July. She badly needs another strong showing to break out of her campaign doldrums.
O'Rourke, meantime, has been lackluster in previous debates, falling well short of his electric performance on the campaign trail. He's chucked the conventional political playbook to turn his candidacy into a fiery crusade against President Trump and in, particular, in favor of stricter gun controls. Will he be more of a factor in Thursday night's debate?
Q. Anything else?
A. Do you enjoy reruns?
A. Warren and Sanders are personal friends and political allies. They made nice on the debate stage in July. The question, again, is whether they end their entente as they seek to broaden their appeal to the same set of political-revolution-minded voters.