To answer the question, one will have to come up with a specific context and demonstrate how the social mechanisms did or did not ensure political accountability.
One context relates to Joseph Biden. During his run for president, a fair amount of people brought attention to the belief that the social mechanisms that lead people to withdraw support for major figures accused of sexual misconduct were, apparently, inapplicable to Biden.
When a particularly graphic accusation became public, many Biden allies cast doubt on its validity. In this context, it appears as if certain social mechanisms aren’t applied evenly. When someone from the opposing party is accused of sexual assault, accountability is required. If it’s someone from one’s own party, then the social mechanism becomes less exacting.
Of course, when it comes to Biden, one could point to different social mechanisms that appeared to apply to other politicians but not to the current president. Throughout the presidential campaign, commentators called attention to how social mechanisms regarding racism did not seem to hold Biden accountable for his past record. In his years in the Senate, Biden was a central part of several laws that had a disastrous impact on people of color. As Biden’s victory in November's election indicates, the social mechanisms meant to punish such behavior did not stop him from becoming president.
Of course, one might argue that Biden’s past record wasn’t intentionally racist or that his new stances make amends for his prior positions. One could also claim that, compared to Donald Trump, Biden’s opponent, Biden was far less problematic, and thus it was more important to hold Trump accountable.