"The Daily Show's" John Oliver compared on Tuesday how Australia passed new gun control laws to the U.S. Senate's failed vote last week on new background check measures. Oliver found one key difference: Politics.

"Last week, we learned that while our Senate was unable to pass even the most basic gun control measures, Australia has had a successful gun control scheme for almost two decades," "Daily Show" host Jon Stewart said, introducing the segment.

Oliver talked to Australian politicians who said they were outed from office because they supported new gun measures after a 1996 mass shooting that killed 35 people. Supporters of Australia's laws cite the fact that Australia had 13 gun massacres in the 18 years before the 1996 gun reforms, but has not experienced any mass shootings since.

Oliver shamed the four Democrats that voted against background checks last week — Sens. Mark Pryor of Arkansas, Max Baucus of Montana, Mark Begich of Alaska, and Heidi Heitkamp of North Dakota.

He mocked them for having the "courage" to "reduce the rate of political suicide" in Congress.

Watch the clip below, courtesy of Comedy Central: