According to the social
contract theory, the contract is

Contract is the agreement between the people who are living in certain society (country for example) on what form of government should exist.

Explanation:

This theory was mostly created during the period of Enlightenment. Philosophers, such as Hobbes and Russo believed that the monarchies that were existing in that period weren't allowing individuals to be involved in the political life of their country. Monarchies were usually absolutistic and were not allowing the changes to occur. That is why these philosophers proposed changes, as the role of the government is to protect natural rights of people.

lincoln won 212 electoral votes to mcclellan's 21 votes, and lincoln beat mcclellan. is the main reason lincoln won in 1864.