What situation is taking place when increasing numbers of voters choose to distance themselves from either party, democratic or republican, and instead consider themselves to be independents?

Dealignment

Explanation:

Dealignment, in political science, is a term used to refer to a large number of voters or electorate who permanently leave their political party and not choose any party to join or not form any political party.

This is a contrast of realignment which occurs when a large number of electorate abandon their party to join another political party.

In the United States ,dealignment is a process of abandoning both republicans and democrats and not associating with any other party.

This will manifest itself through an increase in independent voters.

The most reason that political analyst find is that these people are not happy with all the ruling political parties.

They mostly believe that these parties have similar values and dealignment can also be driven by endless conflict between the two parties which makes people lose their trust in both parties.