Kelly is a Republican and Carlos is a Democrat. Both believe that the members of their political party are more fair-minded and trustworthy than members of any other party. This belief BEST illustrates:

ingroup bias

Explanation:

Ingroup bias -

It is a type of bias situation, where one group of people or a single individual is prefered over others, is known as ingroup bias.

In this type scenario, a person, simple favors or have influence on a group over another.

For example, people supporting a specific sports group, and factor supporting them could be anything like personality of the people nationality etc.

The factor could be race, nationality, religion etc.