As Donald Trump’s campaign comes unglued, its underlying depravity and recklessness can become difficult to keep in perspective.

Thus did President Barack Obama’s Rose Garden comments about Trump, on Tuesday, get folded into the mix of a day’s worth of political news with little note taken of how extraordinary they were.

“[W]e recognize that there is something more important than any individual campaign,” Obama said, “and that is making sure that the integrity and trust in our institutions sustains itself. Because democracy, by definition, works by consent, not by force. I have never seen in my lifetime or in modern political history any presidential candidate trying to discredit the elections and the election process before votes have even taken place. It’s unprecedented.”

Here was the current president of the United States offering the other party’s presidential nominee a basic civics lesson about the peaceful transition of power, as a way of beseeching him not to vandalize American democracy.

Obama went on to goad Trump for whining like a sore loser, and for demonstrating his unfitness for the presidency by blaming others for his losing poll numbers. But what made Obama’s comments really extraordinary is that they were necessary at all. And they were necessary in large part because Republican leaders have decided to tolerate their erratic nominee no matter how dangerous his rhetoric becomes.