About three hours after former President Donald Trump was nearly assassinated, on a Saturday evening in mid-July, Robert F. Kennedy Jr. got a phone call: Would he consider joining forces with Trump? What about serving as his running mate?

The caller was Calley Means, a health care entrepreneur who had advised Kennedy on chronic disease policy. He suggested that it might be a moment for unity ¡ª Trump had just narrowly escaped the same fate that had befallen Kennedy¡¯s father and uncle. Kennedy, who was running an independent campaign for president, said he wasn¡¯t interested in the vice presidency, and the call ended.

A short while later, Kennedy called back. Yes, he said, he would speak with Trump.