I am inclined to say it is a mixture of #1 and #6.
This rightward shift makes more sense if you don't treat Hispanics as a monolith (which is a mistake many Democratic consultants and/or establishment Democratic politicians are making). For example, shortly after the 2020 election, an article appeared in Politico where the author explained that Republican gains in Southern Texas are mostly the result of increased turnout among Tejanos rather than Latinos — the former group refers to people whose families have already been in the US for many generations (and are thus more likely to consider themselves White instead of people of color), while the latter group refers to people who immigrated to the US within the last several generations (and are thus more likely to consider themselves people of color). Similar patterns exist elsewhere in the country — Hispanics whose families came to the US many generations ago are more likely to consider themselves White, and thus require different voter outreach approaches compared to Hispanics who immigrated to the US within the last several generations (and the Biden campaign really took Hispanics for granted, compared to Obama and Hillary).
Differences among Latinos were noticeable in 2020 — there was much less swing in the mountain counties of Brewster and Presidio (which of course have vastly more in common with New Mexico than with any other part of Texas) than in South Texas proper, or in such counties as Miami-Dade and Monroe in Florida, Yuma in Arizona, Clark in Nevada and Imperial in California.
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