It quickly turned into an iconic image. With the American flag as a backdrop, the photo of the bloodied Mr. Trump, fist clenched and urging his supporters to “fight,” is now familiar to every American and people around the world. In our current political environment, it was natural for Mr. Trump to assume that the attempt on his life was the handiwork of his opponents trying to eliminate him. His response was thus understandable in the heat of the moment.

That theory was promptly put to bed, however. It turned out that the attack wasn’t a complex, state-sponsored scheme, but rather the deed of an impressionable young man who, as far as we know, acted alone. At just 20 years old, this November would have been the first time he would have been eligible to vote in a presidential election. We have also learned that he was actually a registered Republican, but had recently made a small donation to the Democratic Party. Quite obviously, his antipathy was toward Mr. Trump personally.

It is impossible to know exactly what would have happened to the country had the bullet killed the former president. But it is reasonable to assume that most likely, all hell would have broken loose, with violent riots all across the nation. America’s police, and probably the military, would have had a massive job cleaning all that mess up.

The fact cannot be lost on any American that it is the nation’s heated partisan rhetoric that motivated this young man to carry out such a heinous act. Lots of people across the political spectrum have to take responsibility for creating this poisonous atmosphere. Mr. Trump himself bears a large part of the blame. That is why I was so heartened by the reports that he has decided to rewrite the speech he is due to deliver tomorrow at the Republican convention in Milwaukee. His near-death experience has apparently prompted him to rethink his combative approach, and is said to be preparing a new speech that will have a more unifying tone.

If that happens, it would be a golden opportunity that the nation must seize with both hands. There are too many people in America today who think that total victory over their opponents should be their only goal. That is a sure path to national ruin.

Steve Bannon, the right-wing Republican who served for a period as White House chief strategist during Trump’s presidency, is currently leading a populist movement to “remake” America. In a recent interview that New York Times columnist David Brooks conducted with Bannon, Brooks suggested to him that most people are pretty reasonable, and that if he engaged in conversations, he would at least see where others are coming from. Bannon’s response was: “We’re not reasonable. We’re unreasonable because we’re fighting for a republic. And we’re never going to be reasonable until we get what we achieve. We’re not looking to compromise. We’re looking to win.” Elsewhere in the interview, Bannon said the following: “There’s nothing to talk about. On the fundamental direction of the country, we are separate. We are two different worldviews. And those worldviews can’t be bridged. Remember, in war, take the moral high ground, totally and completely destroy your opponent.”

That is shocking stuff. It is quite hubristic for anyone to think that their worldview is the only correct one. We call this attitude totalitarianism when we see it elsewhere. Bannon should know that the vast majority of Americans don’t want to live in that type of state.  America urgently needs Republican leaders to take responsibility and get such menacing rhetoric rooted out of national discourse. Someone should tell Bannon that he and his team are not playing a soccer match in which the losing side is just going to shake hands, in a civilized manner, and go home. The result of his approach tends to be ugly guerilla warfare. And he should know that there would be no way for him and his band to escape any ensuing inferno. Democratic leaders should do the same sanitation work with their people on the extreme left.

Politics is often described as a blood sport. But that is supposed to be metaphorical. We shouldn’t be fighting kinetic wars over our elections and have actual blood running down the faces of candidates, as we saw in that photo last weekend. After all, we are the nation that has been running around the globe the past several decades telling people how to practice democracy.

I watched the recent U.K. elections with some envy. There were six short weeks of drama-free campaigning, followed by voting and a swift handover of power, without court challenge, to the winning Labor Party. Apart from its ugliness, America’s electoral system is increasingly looking like its dysfunctional medical system. In healthcare, we spend gazillions of dollars, orders of magnitude greater than that of every other country, but we are nowhere near being the healthiest people on the planet. Likewise, in our politics lately, we splurge billions of dollars over four years, only to end up with malfunctioning governments. We may be the most powerful country in the world, but there is a lot that we can learn from others in some areas.

The silver lining in last weekend’s tragedy (it was, because someone died) is that it has opened the window, even if slightly, for a return to civility in our politics. Apart from Mr. Trump’s reported change of tone, I have heard several leaders of the party who are attending the convention say that they intend to tone down their rhetoric as well. If they make good on those promises, the Democrats will have a responsibility to reciprocate the gesture. This nation has been dancing perilously close to the edge of a cliff. This a great opportunity for everyone to take a deep breath and help pull it back to safer ground.