The situation I pointed out would exist only if there were overwhelming evidence that one side had truly superior policy prescriptions. Public policy isn't science. It is linked to the broader environment (demographics, sociocultural situation, technology, etc.), which is in a continual state of flux. Hence, public policy can't become rigid without losing effectiveness. Moreover, since there is no near perfect policy approach, there is diversity of opinion (liberal, conservative, libertarian, etc.). In a world of change, that diversity of political thought is a strength (and your position articulates that), as effective policy makers can draw from a larger pool of ideas to confront societal challenges and opportunities. Clearly, some extremes have been properly discredited e.g., fascism, but in the mainstream, there is a lot of heterogeneity.
. But yes sutherland.