Kamala Harris becomes President, VP office is empty until she nominates a replacement and they’re confirmed by a majority vote of both houses of Congress, which likely does not happen.
DNC needs to figure out how to select a new candidate, likely using a process they’ve created already but never tested.
RNC already had primaries scheduled, and they’ll remove Trump from ballots where possible, as he’d be ineligible on account of having died, and they continue their primary process. It’s probably between Haley and Desantis in the end, seeing who can pick up more Trump voters. Ramaswami probably becomes a bit more relevant, but still loses.
The media loses their minds, and the people of the Internet make so many references to Death Note.