If media corporations worked together to convince you that a half decent politician is evil incarnate but the politician that helps corporations extort the people is good, what would it look like?

Like say Politician A is a somewhat decent politician that's little bettor or worse then the ones before, but Politician B wants to take away the general people's rights so that corporations can get richer and richer. Corporations band together to make Politician A look like the spawn of Satan with every thing they ever did put under a microscope and blown out of proportion if not outright fabricated, while everything Politician B does is completely buried and debunked by bribed people who are claimed to be experts in their respective fields. What would that look like? Like what's an example of a claim and an example of the actual truth behind it?