It’s certainly going to backfire economically, but I’m not sure about politically.

There are basically three constituencies being served: affluent people who pretend to care about the poor, fairly responsible poor people who want lower rates, and irresponsible people who will lose their lines of credit.

The first two groups will like the policy and there’s little sympathy for the third group. “They shouldn’t even have credit cards in the first place.” strikes me as a likely response.