The concept that completes the fragment is Cross-voting.
Cross-voting is a form of voting in which the elector has the right to vote differently in elections. Cross-voting allows the voter not to favor a single party but can vote for two different parties during an election.
For example, a voter leans for a state government candidate who belongs to the Democratic party, while at the national level he leans for a Republican candidate. He votes for each of them, this is known as a cross vote.
According to the above, the fragment would look like this:
Voting for one party on a state level and the opposite party on a national level is known as Cross - voting.
Learn more about elections in: brainly.com/question/1657299
