A ___ was someone who opposed tyranny.

Democrat

whig

Republican

Federalist

Nationalist

whig

One might argue (or at least hope!) that all American political parties would stand in opposition to tyranny. The fact that you didn't capitalize "whig" tells me that maybe you're using that term in its general meaning, from its origins in English political life. The original Whigs were persons from Scotland who objected to what they saw as the tyrannical rule of England's king Charles I. The term was then used for those who opposed the return to an absolutist monarchy that James II tried to set up in England.

In US history, the Whig Party was formed in opposition to what they saw as an overreach of presidential power by Andrew Jackson. The Whig Party supported the power of Congress over the presidency.