Former Starbucks CEO Howard Schultz says he’s considering an independent run for President to counter what he calls the “revenge politics” practiced by two bitterly divided political parties. The liberal Mr. Schultz has been excoriated on the left because many Democratic activists believe, perhaps mistakenly, that he would inadvertently help President Donald Trump get re-elected.

The vitriol that’s been directed at Mr. Schultz seems to confirm his diagnosis of unhealthy U.S. political debate. And so does the latest news from...