Which principle was included in most state constitutions?

Separation of powers; the early state constitutions all contained John Adam's provision for the protection of the people with property.

freedom of speech is also protected by the 1 amendment.

explanation:

here is pretty much what the 1st amendment says:

congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances.

the answer is that the political parties encourage people to caste vote.