It’s too early to know precisely what motivated either of the shooters who attempted to assassinate President Trump. It is likely but not certain that the most recent was political, as probably were the threats against six Supreme Court justices.

Yet it is not too early to worry that the extremist rhetoric directed against Trump and the conservative justices may have contributed to the atmosphere that encourages the kind of violent acts we are now seeing.  

Nor is this violence-inducing rhetoric limited to the hard left. It has become a staple of MSNBC to compare Trump to Hitler and other genocidal tyrants. Even my former colleague, professor Lawrence Tribe, has crossed all acceptable lines by comparing Trump to Hitler, and by stating that “if you’re going to shoot him [Trump], you have to shoot to kill.”  

Mr. Tribe has since apologized and claimed that he was referring to impeachment rather than guns when he referred to shooting Trump. He also clarified his comparison to Hitler by limiting it to their similar hand gestures. Apologies and clarifications, though, do not get the kind of attention — especially by unstable radicals inclined to violence — that the original violent formulations receive. This is why it’s never good enough to apologize and clarify. One should think hard before making such dangerous statements in the first place.

The comparisons to Hitler, even if subsequently removed or explained, are particularly troubling for several reasons. We honor patriotic Germans who tried to assassinate Hitler, especially during the Holocaust, when he was literally murdering millions of innocent people.  

We should not be honoring, or encouraging, those who would try to kill an American presidential candidate, regardless of what they may think of him. Yet violence-prone potential assassins may think they too will be honored for killing Trump. His most recent attempted assassin apparently wanted to video his “heroic” act for all to see. He too may have expected to be praised— as he surely would have been by some if he had succeeded.

A related problem with any effort to compare Trump to Hitler is that it minimizes Hitler’s crimes and is a form of Holocaust denial or minimization. If all Hitler did was to do or say what Trump has done and said, then there were no gas chambers or mass shootings by the Nazis. In a word — no Holocaust.

This is why decent people generally eschew any comparisons to Hitler or Nazism. But many on today’s anti-Trump left use these false analogies promiscuously and falsely without apparent concern for their potential, even if unintended, impact on violence-prone and possibly unstable potential harm-doers.

The time has come to tone down the violence -inducing rhetoric on all sides of the political spectrum. There are legitimate criticisms that can be made of all candidates for high office without indulging in unnecessary and dangerous comparisons to the worst evils suffered in history.

The current danger is that copycats may try to emulate these assassination attempts. So the Secret Service must increase its protection to the level of a sitting president. Now.