What was immediately likable about Jimmy Carter?

His truthfulness and openness, as he is considered an outsider to the political class

Explanation:

Jimmy Carter, the former and 39th President of the United States, was immediately likable among United States citizens, because he was offering a truthful and open federal government during campaign, and considered as an outsider from the political class.

On of his first acts as a President, was the fulfillment of a campaign promise, in which he granted an executive order, declaring unconditional amnesty for Vietnam War-era draft evaders.