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.
when someone expels gnarley butthole fumes inside a tent while camping. see also portugeuse smokehouse.
we were camping on a frosty december night, and all the windows in our tent were zipped up, when suddenely danny unleashed a brazilian steamroom of nuclear proportions.