Now playing
17:18
Joe Biden's entire Democratic convention speech
Brooke Baldwin last show goodbye CNN newsroom vpx_00000217.png
CNN
Brooke Baldwin last show goodbye CNN newsroom vpx_00000217.png
Now playing
03:56
'Get a little uncomfortable': See Brooke Baldwin's last words on air
CNN
Now playing
02:56
Watch Anderson Cooper belly laugh with Cheri Oteri
Now playing
01:24
How Kyra Sedgwick got the cops called on Tom Cruise
Now playing
05:18
Anderson Cooper explains how he overcomes being shy
US Navy
Now playing
01:28
Pentagon confirms UFO video is real, taken by Navy pilot
Now playing
02:35
WWII veteran: End of the war was 'the biggest thrill of my life'
Fancy Feast/Purina
Now playing
01:06
Cat food company makes a cookbook ... for humans
Google Earth's new timelapse feature
Google
Google Earth's new timelapse feature
Now playing
01:09
Google Earth's new Timelapse feature shows 40 years of climate change in just seconds
Twitter | @brady9dream
Now playing
02:10
Pet owners pitch their pups to be dog brew's 'Chief Tasting Officer'
FOX/"The Masked Singer"
Now playing
01:23
'The Masked Singer' reveals identity of The Orca
LONDON, ENGLAND - DECEMBER 07:  A visual representation of the digital Cryptocurrency, Bitcoin on December 07, 2017 in London, England. Cryptocurrencies including Bitcoin, Ethereum, and Lightcoin have seen unprecedented growth in 2017, despite remaining extremely volatile. While digital currencies across the board have divided opinion between financial institutions, and now have a market cap of around 175 Billion USD, the crypto sector coninues to grow, as it continues to see wider mainstreem adoption. The price of one Bitcoin passed 15,000 USD across many exchanges today taking it higher than previous all time highs.  (Photo by Dan Kitwood/Getty Images)
Dan Kitwood/Getty Images
LONDON, ENGLAND - DECEMBER 07: A visual representation of the digital Cryptocurrency, Bitcoin on December 07, 2017 in London, England. Cryptocurrencies including Bitcoin, Ethereum, and Lightcoin have seen unprecedented growth in 2017, despite remaining extremely volatile. While digital currencies across the board have divided opinion between financial institutions, and now have a market cap of around 175 Billion USD, the crypto sector coninues to grow, as it continues to see wider mainstreem adoption. The price of one Bitcoin passed 15,000 USD across many exchanges today taking it higher than previous all time highs. (Photo by Dan Kitwood/Getty Images)
Now playing
03:07
Bitcoin has an energy problem
The new all-electric Mercedes-EQS
Mercedes-Benz AG
The new all-electric Mercedes-EQS
Now playing
01:05
See the new all-electric EQS luxury sedan from Mercedes
Now playing
01:32
Scientists turned spiderwebs into music and it sounds like a nightmare
Jeopardy Productions, Inc.
Now playing
01:02
Aaron Rodgers' Green Bay Packers question stumps 'Jeopardy!' contestants
Now playing
05:18
Coinbase CFO: We're an on-ramp to the crypto economy
(CNN) —  

Back when I was at The Washington Post, I would occasionally engage in long email conversations about politics with my longtime friend – and the Post’s senior Capitol Hill correspondent – Paul Kane. PK’s insights were so good that we often published our exchanges so I could share his thoughts with readers. Now that I’m at CNN, I still value PK’s wisdom about Congress – and politics more generally.

So when Joe Biden embarked on his media tour for “Promise Me, Dad” – a memoir of the year in which his eldest son died from brain cancer – I reached out to PK to talk about the former vice president and his future political ambitions, including a potential 2020 presidential bid. Our email exchange is below – edited only slightly for flow.

Chris: OK, PK. We may be at different media organizations but through the power of electronic mail, we can still communicate!

Let’s talk Joe Biden. He’s been all over the media in the last 72 hours – he was on the “Today” show so much on Monday I thought he had been hired as a new anchor – promoting his new book about the death of his son, Beau, and his life up until now.

In these interviews, he has the same pat response about 2020: If I had to decide today, I wouldn’t run. But I am not shutting the door on it for 2020.

Two questions:

1. Do you believe him that he wouldn’t run if he had to announce today? (I sort of don’t.)

2. What makes up his mind – to run or not run – between now and, let’s say January 2019? Is it external stuff? Personal things? Both? Neither?

PK: Greetings old friend. How is it working with Mark Preston again? OK, don’t answer that question, it would involve too many expletives and would divert us from the topic at hand, Biden.

First off, it should be noted that the frame of this book – “Promise Me, Dad” – was crafted long before Donald J. Trump was sworn into office. It actually was crafted in expectation that Hillary Clinton would be president and Biden would be almost solely focused on the cancer moonshot.

I wrote a piece over several months in 2016 about Biden’s heavy focus on stumping for Senate Democrats, trying to flip the majority last fall. On one trip, flying from Los Angeles back east in September 2016, he told me about the book proposal: a year in his life, from learning Beau’s cancer was back, to watching him fight for his life, to his death, to America’s outpouring and his consideration of a late-breaking bid for president, to him standing in the Rose Garden with Obama and Dr. B, saying he wouldn’t run.

He wasn’t even sure he could write the book, given the emotional ground he would have to plow.

So, this book itself is not the usual presidential campaign book. It was originally meant to be a bookend to his career. But life and circumstances change, sometime in a moment’s notice, sometimes over several years, and no one knows that better than Joe Biden. So now he sits among the top tier of the type of people who would be mentioned in 2020. I think the answer to your two questions are unknowable, because the first scenario is actually more like a UK-style snap election – and that’s the sorta campaign Biden would be most likely to run, a brief sprint of a few months from nomination to general election. But those don’t exist in America.

So, question two is more important, and I think Biden is being pretty open and pretty honest when he says that he’s waiting to see how the field develops. He wants to be president, of course, he’s ridiculously open about that ambition. But he also knows that change elections don’t usually go to 77-year-olds who spent 44 years in federal office.

Over the next 18 months he’s waiting to see if someone, even a few people, emerge as real credible contenders to Trump. Because, at the moment, no such person really exists.

Chris: Preston’s new glasses deserve their own Twitter feed. (And yet, there are NO pics of him in the glasses on Google Images. I smell a conspiracy.)

On Biden’s age: He would be, of course, the oldest person ever to be elected president. He would take that record from one Donald John Trump, who was elected at age 70.

Which sort of gets me to my point: We are living way longer. Our politicians, not surprisingly, are also living longer – and running for (and staying in) office longer.

The top tier of the 2020 field is not exactly spring chickens with or without Biden. Bernie Sanders will be 79 on election day! Elizabeth Warren will be 71. Hell, Trump will be 74 on Election Day 2020!

That’s my pro-Biden point.

My anti-Biden point is this: Everyone – myself included! – put him in the top tier of potential 2020 candidates. But, that – admittedly early – handicapping is based solely on the fact that he spent eight years as Barack Obama vice president. After all, Biden’s own record as a presidential candidate is way less impressive. He dropped from the 1988 presidential primary in 1987 after a plagiarism scandal. In 2008, he was never close to being a serious contender and never, really, had a moment in which he appeared to be building momentum in the race.

So, aside from having been picked by Obama to be vice president, what’s the convincing evidence that Biden would be a great presidential candidate befitting his top tier status?

PK: OK, I’ll start with your last point/question, then work back to the age issue.

Biden belongs in the top tier both because he served as Obama’s VP, giving him universal name ID, and because of his deep knowledge of foreign policy that began through a couple decades of service on the Senate foreign relations committee. Those are top-tier credentials. Furthermore, and perhaps most importantly, Biden has, better than any Democrat at the national level, cultivated an everyman image that has an appeal to voters in white working class exurban areas near Scranton and to inner-city black neighborhoods of North Philadelphia. No one will ever accuse Biden of being an elitist.

That trip I mentioned earlier, from LA to back east, that was the night that Clinton made her “deplorables” remark at a fundraiser. He had just spent 20 minutes lamenting how his party had become perceived as the party of “pedigree,” the party of Ivy elites. His head exploded when we relayed to him the full quote of what Clinton had just said.

All of that gives him an appeal to the voters that Democrats lost from 2008 and 2012 to 2016 – particularly those across the Midwest, in places like Erie, Pennsylvania; Toledo, Ohio; Macomb County, Michigan; Racine, Wisconsin.

But, but, but, you can’t talk about Biden being in the top tier for 2020 without first addressing the issue of age, and as it relates to how voters will view it and also whether or not it’s the right idea for the nation. Biden’s own health has been pretty good for a 74-year-old, for sure, and his mother lived till she was 92.

The issue won’t necessarily be whether he’s fit to serve come January 2021, but what toll the presidency takes on even the healthiest of people. He turns 75 next week. In the fall of 2024, he would be presumably running for re-election at the age of 81.

Put another way, if Biden served two terms, he would turn 86 on November 20, 2028, as he was passing the Oval Office to his successor. The distance from 74 to 86 is big for any human, let alone one that would spend eight years of that span in the toughest job in the world.

I’ve watched, up close, as number of senators who were incredibly sharp and energetic in their mid-70s, turn very slow and plodding by their early 80s. We have to think, as a society, whether we want the leader of the free world to be challenging Father Time.

Chris: So, that’s interesting. I hadn’t thought of the age issue as much as you have. It’s true that Biden would be super old – that is a technical term – if/when he ran for re-election. At the same time, Trump will be 74!

Anywho. Let’s assume – and you are convincing on this front – that Biden is a top tier candidate along with either or both Warren and Bernie. What’s your sense for what that race looks like?

My strong sense is that either or both Warren and Sanders seek to cast Biden as establishment. As too centrist. Too compromise-oriented. Clinton 2.0. (Or 3.0) (Or 4.0). (Yes, I know it is ironic that Biden would be cast as the heir to Clintonism given his stated disdain for the campaign Clinton ran in 2016.)

Do you agree? And what’s your sense of how Biden would respond to that characterization/attack?

PK: To be sure, I’m not saying that Biden, or anyone in their 80s, cannot do the job. It’s just a serious issue, and yes, I’ve seen it firsthand, in my own family, watching someone go from completely with it and snappy in their late 70s, to wheelchair-bound by mid-80s. And I’ve seen the drift of a bunch of senators in the last six years or so. It’s tough.