U.S. Rep. Steve King of Iowa has set off a social media storm Monday after telling MSNBC's Chris Hayes that whites have contributed more to Western civilization than any other "subgroup."

King’s comments came during a panel discussion about diversity within the GOP and at the Republican National Convention in Cleveland this week — which one of the panelists, Esquire’s Charles Pierce, said was dominated “by loud, unhappy, dissatisfied white people.”

King responded by asking: “Where are these contributions that have been made by these other categories of people that you’re talking about? Where did any other subgroup of people contribute more to civilization?”

When Hayes asked whether King meant white people, King said it was “Western civilization … it’s rooted in Western Europe, Eastern Europe and the United States of America and every place where the footprint of Christianity settled the world.”

The reaction was swift, especially on Twitter.

Among those taking aim was Atlanta resident and New York Daily News columnist Shaun King: "That exact moment where Congressman Steve King goes full white supremacist. An ahistorical mess. Textbook racism: https://amp.twimg.com/v/4a958728-0c64-4c39-add2-df70903c5cd3."