Former Secretary of State John Kerry spoke a fundamental truth about how difficult it is to take back public statements.

Donald J. Trump said the patently wrong thing about the violence that erupted over the weekend in Charlottesville, Va., calling an end to violence “on many sides.”

Rather than single out the white nationalists, neo-Nazis and Ku Klux Klansmen who initiated the violence, Trump chose instead to equivocate shamefully.

Well, he took a baby step toward redemption today by singling out the racists and bigots who gathered in Charlottesville to protest the taking down of a statue of Confederate Gen. Robert E. Lee. Many observers have noted that the president seemed a bit uncomfortable today as he delivered his prepared remarks.

Kerry, though, said you can’t “take back” the “many sides” comment. Kerry called the president’s first response “revealing” and said they had empowered “the worst of the worst.”

Trump tried to take it back but failed, according to Kerry.

I’m reminded of what my late friend and former colleague Claude Duncan was fond of saying: “You can’t unhonk the horn.”

Indeed, people in high places aren’t usually allowed to take mulligans. There aren’t any do-overs — especially for the president of the United States, whose words resonate and keep resonating long after he utters them.