Antonyms for "does one part" could include phrases such as "neglects responsibility," "doesn't contribute," or "abdicates duties." Alternatively, antonyms could also include phrases that emphasize a more active role, such as "takes the lead," "fully participates," or "carries out responsibilities." Depending on the context, an antonym for "does one part" could be a phrase that highlights a lack of engagement or involvement, or one that emphasizes a proactive approach to fulfilling obligations. Ultimately, the antonym will depend on the specific context and the desired emphasis or contrast with the original phrase.