Anyway, what Biden should do based on the above analysis:
1) Feel their pain. Stop pretending prices aren't higher and many things aren't less affordable, including mortgages. Admit that this is causing hardship and show empathy. Admit that a lot of this is due to the decoupling of the world's two largest economies but say that it is necessary to contain China. We all have to belt tighten to beat China and contain it. Turn it into a "what you can do for your country" type thing.
2) Fearmonger like hell over Trump's proposed tariffs that he wants to put on everything. Make ads of ordinary people facing ridiculously high prices and and tie it to Trump's promised tariffs in his second term. Turn the inflation issue into something to attack Trump on. Turn it into a "big loaf, little loaf" election where he's populist from a free trade perspective, like the 1906 UK election.
Biden is proposing tariffs himself, so 2 is unlikely to work. Biden would clearly be doing better if he did 1, but he seems unwilling to do this, instead running ads about how the economy is the greatest in the world and denying any problem in a CNN interview.
