One option a member of Congress can follow for how to cast a vote is as , or person who has been given power to act for others.
a trustee
a partisan
a politico
a delegate

A trustee

Explanation:

It's a person who has been given power.

if you could provide the poem below, i'd be happy to you!

explanation:

you didn't give us the poem, or the title of the poem. but it is essential for you to give us that, otherwise we can not detect when the poem has a tonal shift!

basic principles: federalism, separation of powers, checks and balances, judicial review, representative democracy, limited government, rule of law, individual rights and responsibilities, consent of the governed, majority rule, popular sovereignty, equal protection.