It was an extremely weak mandate, and in normal times (e.g., assuming the concept of limited government), a weak mandate would be a mandate to act with restraint. Thus a "mandate" doesn't justify what's happening.

The Republicans abandoned the economic debate, and shifted focus to social issues. This is what caught the Democrats, including myself, off guard. Rather than stealing our jobs, the immigrants were accused of stealing our cats.

Framing it as an economic issue in hindsight seems like a polite way of "steelmanning" the voting base, but I'm not sure it's really justifiable.