Answer:
Smith meant that the president's sins were too serious for him to be seen as a saint, even if forgiven. However, the colonists' sins were less serious sins and could easily be atoned for.
Explanation:
Smith was criticizing the president, showing that he was a vile man with heavy and grave sins against the people, against the nation and against God. Even with forgiveness, the president was already corrupted and would never be seen as someone free from sin, he would never be accepted into Sainthood, because sins made him a lost and unsaved case.
The colonists, in spite of presenting sins, could be absolved of their faults and become pure, manageable and holy men, because their sins were light and less degrading.