By John Kanelis / johnkanelis_92@hotmail.com

United Nations Ambassador Linda Thomas-Greenfield had the temerity to tell a truth that few of us want to hear, but which we all need to hear.

CBS News put this out on Twitter: Amb. Thomas-Greenfield said this week “the original sin of slavery weaved white supremacy into our founding documents.” She tells @margbrennan “Our country is not perfect, but we continue to perfect it. Those imperfections are part of our history, we have to talk about them.”

Let’s understand a couple of things.

Ambassador Thomas-Greenfield is an African-American with extensive diplomatic experience. She’s not flaming fanatic, a novice.

The second point is this: The founders did not get rid of slavery. Many of them were slave owners themselves. They kept black Americans as property. The Constitution did not even recognize specifically that black Americans were entitled to the full rights of citizenship, even though they wrote that “all men are created equal.”

Dichotomy, anyone?

By almost any objective analysis you can use, you can determine that the founders implied that white men — the only Americans who could vote at the founding of the republic — were, uh, superior to anyone else.

Yet the U.N. envoy is getting plenty of blowback. I ask … why? She spoke — to borrow a phrase — an “inconvenient truth.”