A member of Congress is arrested and convicted of failing to pay the proper amount of income tax. Which of the following core American values is most relevant to this case?

The core American value which is relevant to this case is:

Equality.

Explanation:

This concept simply means that under the US law, all citizens are treated equally.  The way a Congressman or woman is treated is the same way that a non-Congressman or woman is treated.  If a non-Congress member fails to pay the proper amount of income tax, he or she will be arrested and convicted, just as the member of Congress is arrested and convicted for the failure to pay the proper amount of income tax.  There are no unjust privileges attached to any person's office or position.