unpersuadable
Speech parts
1. unpersuadable - Adjective
2. unpersuadable - Adjective Satellite
Meaning
not susceptible to persuasion
Source: WordNetSynonyms
Examples
Campaigns fail if they waste resources courting voters who are unpersuadable or already persuaded. Their most urgent task is to find and persuade the few voters who are genuinely undecided and the larger number who are favorably disposed but need a push to actually vote.