So... FOR MY ENTIRE LIFE saying "October Surprise" has been a cue for All Reasonable People to dismiss you as a tinfoil-hatted conspiracy theorist.

Mr. Connally did not figure in those investigations. His involvement, as described by Mr. Barnes, adds a new understanding to what may have happened in that hard-fought, pivotal election year. With Mr. Carter now 98 and in hospice care, Mr. Barnes said he felt compelled to come forward to correct the record.

“History needs to know that this happened,” Mr. Barnes, who turns 85 next month, said in one of several interviews, his first with a news organization about the episode. “I think it’s so significant and I guess knowing that the end is near for President Carter put it on my mind more and more and more. I just feel like we’ve got to get it down some way.”

Mr. Barnes is no shady foreign arms dealer with questionable credibility, like some of the characters who fueled previous iterations of the October surprise theory. He was once one of the most prominent figures in Texas, the youngest speaker of the Texas House of Representatives and later lieutenant governor. He was such an influential figure that he helped a young George W. Bush get into the Texas Air National Guard rather than be exposed to the draft and sent to Vietnam. Lyndon B. Johnson predicted that Mr. Barnes would become president someday.