A person who flattens any meaningful
discussion about an event by
constantly relating it back to a single issue, e.g. income inequality,
immigration, race, "Christian values," feminism, etc.
The debate moderator was asking
questions about
foreign policy, but Bernie Sanders just kept bringing it back to income inequality. He's a total steamtroller.
Grandma turns into a steamtroller once she starts talking about immigrants at
Thanksgiving.