Covering Mr. Sanders is at times like watching a man almost surprised by his success and eager to make it last. And Mr. Sanders, a senator from Vermont who rarely attracted more than a handful of reporters on Capitol Hill, is now trying to convince the news media that, despite his lagging delegate tally, his cause is not lost.

Unlike our colleagues, especially those who cover Hillary Clinton, we in the Sanders press corps rarely lack access to the candidate. Mr. Sanders holds midair and plane-side news conferences regularly, taking questions from as many as a dozen journalists. I went hiking with his campaign aides through the Grand Canyon before the Arizona primary, and have chatted extensively with his wife, Jane, who sometimes serves bags of trail mix to reporters on late-night flights. Mr. Sanders learned early on how to pronounce my name, which not everyone gets right. (It’s YAH-MEESH.)

It may not surprise you to hear that Mr. Sanders rarely strays from his message, even as reporters traveling with him search for fresh angles amid his laments about “millionaires and billionaires” and his promise of a “political revolution.” But he can be aware of the limits of his endless recitations.

I remember talking with him in a small side room in January in Iowa as hundreds of supporters waited for him to speak. As our conversation wrapped up, I asked Mr. Sanders how he would tailor his message to voting blocs in the coming state primaries and caucuses. Instead of responding directly, he began repeating part of his stump speech, which I have now heard more than 90 times, explaining that the American middle class is disappearing and that almost all of the new income is going to the top 1 percent.