Final answer:
The given statement is an example of a credibility appeal, also known as an ethical appeal or ethos, which relies on the character and trustworthiness of the individual.
Step-by-step explanation:
The statement “I can attest to the fact that Mark Johnson’s character is above reproach. His entire life has been devoted to the service of this community. He will be an excellent representative of the people of our town to the state legislature.” is an example of a credibility appeal, which is often referred to as an ethical appeal or ethos. The speaker is vouching for Mark Johnson's character and his lifelong service, which are elements that contribute to his credibility as a candidate for the state legislature. This type of appeal often focuses on the character, trustworthiness, and authority of the individual in question, emphasizing their suitability or competence based on their personal virtues and history.