Whatever Christie is doing, it’s aimed for after the election. I think he’s simply raising his profile for either a talking head spot on a network or a leadership role in the party post-Trump. I think he seriously underestimates the degree to which the party has shifted hard right, though.
Whatever ends up happening, it is going to be wildly entertaining seeing Christie trash Trump at the debates. I think he’ll ridicule Trump for not even having the guts to be present for the debates, and that may trigger Trump to start participating.
This is why he’ll win. Because Republicans live in an echo chamber where they think Biden is incompetent. If you look at the record he’s the best president since FDR.