To increase the inclusion of different parties and reduce fear induced rhetoric about who people should vote for, all elections within the U.S. should be required to use ranked voting. In ranked voting, people place all candidates for a position in ranked order, and if their first choice does not have the requisite votes to succeed, their 2nd choice is used.
This will eliminate arguments about "wasted votes" and reduce the power of establishment candidates to fear monger their way into office. This is a far superior voting system and puts more power in the hands of the people.
You can read more about ranked voting here:
https://en.wikipedia.org/wiki/Ranked_voting_system