Donald Trump’s use of violent rhetoric hit a new, troubling low earlier this week with his comment that supporters of the US Constitution Second Amendment (which protects the right to keep and bear arms) might consider action against Hillary Clinton if she wins the Presidency. She will appoint judges to the US Supreme Court who are anti-Second Amendment, he said. Gun owners might do something in response, he suggested.

His defenders – who usually say that his willingness to say what he means is his most attractive feature – said he had been misunderstood. He was only referring to voting against Hillary, but that makes no logical sense because he was talking about taking action after she had won the Presidency. Perhaps he meant that judges appointed by Hillary should be shot instead? As though that’s any better.

Episodes of political violence have punctuated American history. Trump’s willingness to invoke dark forces, to fuel further the rage of those who are angry already, is the equivalent of playing with matches in a petrol station.

It is terrific, then, to see the daughter of Republican President Ronald Reagan speak out so clearly and calmly about Trump’s veiled threat to Clinton. Patti Davis< was the “black sheep” of the Reagan clan, a liberal who protested against her father’s administration and nuclear weapons and then wrote a tell-all memoir that caused much family angst. She recanted later, and has spoken since movingly of her dawning realisation that she had caused her father hurt and that rhetoric can have dangerous consequences.

Last night she had this to say about Trump:

“To Donald Trump: I am the daughter of a man who was shot by someone who got his inspiration from a movie, someone who believed if he killed the President the actress from that movie would notice him. Your glib and horrifying comment about “Second Amendment people” was heard around the world. It was heard by sane and decent people who shudder at your fondness for verbal violence. It was heard by your supporters, many of whom gleefully and angrily yell, “Lock her up!” at your rallies. It was heard by the person sitting alone in a room, locked in his own dark fantasies, who sees unbridled violence as a way to make his mark in the world, and is just looking for ideas. Yes, Mr. Trump, words matter. But then you know that, which makes this all even more horrifying.”