To elect someone is to choose that person for a position in government or some other organization.
The team members elected a new captain.
Voters elect their representatives.
Barack Obama was elected President in 2008 and 2012. (This sentence uses "elect" in the passive voice, past tense.)
Who would you have wanted to see elected President in 2016? (Whether you live in the United States or not, this is how to ask about a past, alternative outcome.)
The word "elect" can be used to describe situations that are not elections but do involve a choice. In this case, an infinitive often follows the verb "elect."
The company elected to move its headquarters to a new location.
The patient elected to have the surgery done with only a local anesthesia.
The words "elective" and "electoral" are adjectives.
Most elective medical procedures are not covered by health insurance.
In addition to the general course load, students need at least three elective courses. (elective course = an extra course, usually one that reflects a personal interest.)
Donald Trump won the electoral college vote, but Hillary Clinton won the popular vote by over three million votes.