When Michael Bennet’s office called to say he had a big announcement to make, I assumed he would be confirming what everyone already knew — that the Colorado senator would be joining John Hickenlooper and the rest of the ever-expanding Democratic field running for president. And, also, that though he understood he would be a long shot, he figured at this point, without a clear favorite, that it could leave an opening for someone like him — the umpteenth senator to announce.

When Bennet got to the phone, that is, in fact, what he did say. But it wasn’t all he said or nearly the most important thing he said and definitely not the most scary thing he said. Which was this:

Just as he had finally become comfortable with his decision to run, he went to get a physical and received very discomfiting news from his doctor — he has prostate cancer.

His PSA was high. The biopsy showed malignancy. The doctors recommended that, at his age, surgery was the best course of action. His family agreed. The risk, he was told, was low. John Kerry had survived, cancer free, the same surgery in 2003 and two weeks later was back on the campaign trail, on his way to winning the Democratic nomination. And so …

And so, now Bennet is still committed to running for president if — and it’s an important if, but an if that Bennet says he’s at peace with — he will be cancer free. The surgery to remove the prostate gland is scheduled for soon after the congressional spring recess, which begins on April 11.

When I asked Bennet how he was taking all this — the cancer, not the presidential bid — he said he was OK. “I’m too busy to really sit back and think about it,” he said, “and that’s probably the best thing.”

Leave this field empty if you're human:

But it’s one thing to be healthy and make the grueling, unforgiving run for president when no one is actually begging you to do it and quite another to make that decision when you’ve been told you have cancer.

Bennet explains that he decided to get into the race after finishing his book — “The Land of the Flickering Lights”, which comes out in June — and realizing that no one in the field was talking about the reasons for the dysfunction he sees on a daily basis in Congress and how the money and corruption there have put our republican democracy at real risk. As he puts it, after 10 years on the job, “I am shocked every day” by how little gets done there.

“The idea was to announce sometime in April,” Bennet said. “That was the plan. We hired some staff. We interviewed people for positions in New Hampshire and Iowa. And then I went for the physical. In my last physical, my PSA was high. They did a biopsy, and it was clear. But this time, it was not clear.

“That was 2-3 weeks ago. I was in San Francisco. Then the question became: Is this still something I wanted to do? I could answer the question in two ways. Maybe this would be a good time to give it up and go do something else. And the other was whether I could continue to run. I found myself hoping that I could run. That’s what the doctors have said. That’s what John Kerry and others learned.”

One in nine men is diagnosed with prostate cancer over a lifetime, but only 1 in 39 will die from the disease, which is the third most common cause of cancer deaths among American men. In 2017, the American Cancer Society estimated that more than 160,000 men would be diagnosed that year and 26,730 would die. Many of the deaths come when the disease has never been diagnosed.

“I’m 54,” Bennet said. “That’s relatively young. It seemed to make sense to have the prostate removed … I’d be recuperating for 7-10 days and would need some rest after that. The hope is then I’ll be cancer-free and able to move on. If I’m not cancer free, then I’d have to make another decision.”

And then to show he’s in run-for-president condition, Bennet went full wonk on health care, an issue he has been passionate about for at least as long as the 10 years he has been in the Senate.

“In all honesty, I know nobody likes being told they have cancer, but I see myself as actually having been lucky,” Bennet said. “It was detected early. It is highly treatable. I have insurance through Kaiser Permanente. I feel lucky that the doctors found it. I feel lucky that I’ll probably be OK.

“The reason I wanted to share this is that I didn’t want anyone to make it other than what it is — a brief healthcare speed bump. Having said that, it is a reminder of how important it is for people to have health insurance and to have primary care checkups.

“I don’t want to be hysterical, but if it was left in me undetected, it could kill me. It won’t because I have insurance and decent medical care. The idea that the richest county in the world hasn’t figured out how to have universal health care is beyond embarrassing. It’s devastating.”

Bennet watchers have noticed — actually, couldn’t miss — the new passion he has been showing on the Senate floor and in TV interviews. There was the viral video, breaking CSPAN video records, of his now-classic takedown of Ted Cruz. On the Senate floor Wednesday, he spoke emotionally of Mitch McConnell’s latest nuclear-option scheme, a procedural move to short-circuit debate on some executive and judicial nominations.

“Today’s votes will represent the latest degradation of the Senate’s responsibility to advice and consent,” Bennet was saying. “The integrity of our rule of law demands that we escape this spiral of retaliation over judicial nominees, not hasten it …The partisan temper that is destroying this place needs to come to an end. And we need to make sure that between now and whenever that happens, we don’t take down the rest of government with us.”

Bennet’s fervor has been a warm-up for the big run, but the emotion, as NBC’s Kasie Hunt put it, seems authentic coming from a normally mild-mannered senator. Bennet’s answer for why he’s running is this: “I finished the book. I didn’t think the case that I made in the book was being articulated by anyone in the field. I wouldn’t do it if I didn’t think I had a chance to win. I think, like everyone else does, it’s a long shot. But I think everyone in the field is a longshot.”

And then he tells me advice he heard that Barack Obama had once given: “You need to tell your wife that everyone is going to tell her that you’re crazy to do this because that’s what everyone told Michelle.”

Bennet laughed. He is ready to bring the world back to normal, or at least as normal as a presidential campaign can be. Obama was a long shot, of course, when he announced. Bennet, who was an early Obama supporter, is a far greater long shot and one who faces cancer surgery this month. If it turns out that in a few weeks people are telling him he’s crazy to run, that would be the best news he could hope for.