I've seen this pointed out, and absolutely do not see it as a problem. What's wrong with politicians paying more attention to the needs of more people?
They're going to campaign somewhere, why should they pay more attention to Cleveland, Ohio (metro area population ~2m) than Los Angeles (city population 3m, metro population over 13m)?
They're going to campaign somewhere, why should they pay more attention to Cleveland, Ohio (metro area population ~2m) than Los Angeles (city population 3m, metro population over 13m)?