He resigned because he'd already had enough trouble as president. Mainly the Watergate scandal. His plan was for him to step down and if he was arrested the vice president which would then be the vice president would pardon him. Also, if he didn't resign he'd likely be impeached anyway.
Answer:
Jackson's great political powerful was attributable not only to his forceful personality and remarkable background as an Indian fighter and military hero. ... Another notable Jackson enemy was John C. Calhoun, who had actually been Jackson's vice president before things between them turned bitter.
It helps to protect the rights of the accused
The first answer is correct