Upon performing a close analysis of the character of Arthur Dimmesdale, we find clues in his "story" that could help us reach the actual center of his character and decide whether he is, in fact, doomed from the start to make a serious error in judgment.
We learn that Arthur Dimmesdale has always enjoyed the esteem, respect and superior admiration of his flock. This is because Dimmesdale's upbringing shows higher intellect and sophistication which would make him quite salient from among all the other villagers.He is also comparatively young and his charismatic personality, along with his truly philosophical traits, have created a very attractive persona; perhaps a little too attractive for his own good.
As the narrator tells us in chapter IX, Dimmesdale's future had always been seen in a positive light:
The young divine, whose scholar-like renown still lived in Oxford, was considered by his more fervent admirers as little less than a heaven-ordained apostle, destined, should he live and labour for the ordinary term of life, to do as great deeds for the now feeble New England Church, as the early Fathers had achieved for the infancy of the Christian faith.
We can see Dimmesdale, the man when he came straight from Oxford to be lionized by a group of idol-hungry villagers, as a young man whose vanity takes the most of him. At all times throughout the novel Dimmesdale, even after sinning over and over, continues with his idealistic view of himself as a great spiritual man. He cannot move himself from that position even when his own actions tell him that he is not what he thinks that he is. Therefore, the false sense of awareness that forever follows Dimmesdale, combined with the vanity that comes from being placed on a moral pedestal, make his proneness to make an error in judgment quite high. He trusts his "character" too much to think that things will ever go wrong for him. He has charmed the villagers, and he lives on that false sense of sanctity until the very end. In this way, he was doomed to make an error in judgment.