Jack Kemp. Joe Lieberman. John Edwards. Sarah Palin. Paul Ryan. All ran for vice-president of the United States and fell short. All had to confront the question: what next? The same fate befell Tim Kaine, whose turn as running mate to Hillary Clinton in 2016 ended in a catastrophic defeat by Donald Trump and Mike Pence. The US has not recovered, as polarisation, rancour and looming criminal trials testify. But Kaine has. At 7.30am on the Monday after the 2016 election, the Virginia senator was back at work in his office. With Trump in the White House, the work of the Senate proved critical, including preserving Barack Obama’s signature healthcare law. But as time wore on, Kaine found ways to nourish his soul – not on the campaign trail but the nature trail. To mark his 60th birthday and 25th year in public office, he invented his own triathlon in Virginia. On weekends and in Senate recess weeks, Kaine hiked (mostly solo) the 559 miles (900km) of the Appalachian Trail that is in the state, biked 321 miles (517km) along the crest of the Blue Ridge mountains and canoed all 348 miles (560km) of the James River. He kept a 100-word-a-day diary on his phone, raw material for his first book, Walk, Ride, Paddle. The hike was the toughest, he recalls, averaging about 14 miles (22km) a day with a 30lb (14kg) backpack, mostly in the heat of August. “I’d have two litre bottles and I’d be getting down to no water and I’ve got to get to this next stream and I’d get there and it’d be bone dry and then oh, man, talk about depressing!” the 66-year-old tells the Guardian. “The physical challenge of the hike was very difficult. It wasn’t probably till I got to mile 300 that I quit thinking about ‘I don’t need to do this whole thing. Why be so type-A about it?’ But when I passed mile 300 and I only had 260 left, it’s like, I’m going to finish this but I don’t have to rush.” A former teacher and civil rights lawyer, Kaine is one of only 30 people in US history to have been a mayor, governor and senator. In person, in a conference room on Capitol Hill, he lives up to adjectives that often tail him: affable, genial, nice. Only in politics does that count as an insult. In 2016, the New Republic ran a headline: “Tim Kaine Is Too Boring to Be Clinton’s Running Mate.” The Washington Post wondered: “What’s a nice guy like Senator Tim Kaine doing in a campaign like this?” Kaine himself quipped on NBC: “I am boring. Boring is the fastest-growing demographic in this country.” True to form, no one should look to Walk, Ride, Paddle for tales of Teddy Roosevelt-esque derring-do. Like other vice-presidential near misses, Kaine never quite became a celebrity. To those who encountered him in the great outdoors, he was just another guy in baseball cap and hiking shorts. He recalls: “I would say maybe a quarter recognised me and of that quarter, half didn’t say they recognised me. You’re out on the trail to relax and they get that. I learned there’s a beautiful Emily Dickinson poem about once being famous: Fame is a bee. It has a song— It has a sting— Ah, too, it has a wing. “People would see me and if you see somebody and they’re not dressed the way you normally see them, you’re like, ‘I think I kind of know you, but I’m not sure.’ Sometimes people would know me. Most often they wouldn’t. And then sometimes they were, ‘I think I know you. What do you do?’ ‘I work in Washington.’ ‘What do you do in Washington?’ ‘I do some stuff in politics’. ‘What?’ ‘I’m a United States senator.’” The journey took about 30 months, from May 2019 to October 2021, a jaw-dropping period of American history that spanned two impeachment trials, a global pandemic, racial justice protests, a presidential election and the January 6 attack on the Capitol. When the Senate was in session, Kaine had a key part to play. When in nature, he could tune out the noise and contemplate his faith in friendship, God (he grew up in an Irish Catholic household) and America. He likens the experience to a camper who wakes up, stuffs everything into their backpack and gets going. “I realised in the course of the hike that’s how I dealt with 2016. I showed up right back to work. I started working. I said, ‘I’ll sort it all out later.’ “The hike was primarily by myself. That extended time, both the solitude but also the appreciation of nature and your humility in the grand scheme of things, was helpful in taking the stuff out of the pack that needed to be washed and folded and put away the right way.” His epiphany came not around how Trump won, or relitigating what mistakes the Clinton-Kaine campaign might have made, but reckoning with a deeper question: why is America going through this dark chapter? Early one morning, Kaine was hiking alone in fog and rain and nearing Mount Rogers, the highest peak in Virginia, when he thought about the biblical Book of Job. A faithful man who has it all, Job starts to lose his family, his business, his money and his health, compelling him to ask if the universe is pointless and neighbours to assume he is suffering divine retribution. Kaine says: “There’s two explanations of why people or maybe nations suffer: because you did something wrong or maybe it’s just all pointless and random. The reader of the story knows that neither is the case: Job’s being tested. The end of the story is, as mad as he is at God, he still is true to his principles and then what was lost to him is restored.” Kaine was just days away from Trump’s first Senate impeachment trial. “I’d never been on a jury ever in my life, even on a traffic case. I’m just like, I’m 61 years old and I thought I understood this country. What’s going on here? “It’s not necessarily punishment and it’s not necessarily random, but it could be a test. So we stay true to our principles. Belief in religious equality – are we going to kick Muslims around? Our belief in free press – are we going to expose journalists to intimidation, rule of law? No person should be above the law. “I started to think about the virtues that we claim about ourselves, some of which are truer than others, none of which we can perfectly attain. But maybe this is one of these moments to see whether we’re going to stay true to principle or abandon principle, and if we stay true to principle, maybe we’ll end up sadder but wiser but we’ll turn a corner and feel like we’ve passed. I think we’re surviving the test but I don’t think we passed it yet.” No test was more severe than January 6, when Trump supporters stormed the Capitol in an attempt to overturn Joe Biden’s win. Having become less addicted to his phone during his communions with nature, Kaine forgot to take it into the Senate chamber. “It was hours after the beginning of the attack, when we were finally over in a committee room and they turned on TV monitors, that I realised, ‘Oh, man, this is what my parents are seeing, this what my kids are seeing, this is what my wife was seeing.’ So, ‘[Senator] Martin Heinrich [of New Mexico], give me your phone, I got to call people quick!’ “It was a day that I never would have imagined, never will forget and hope is never repeated. It was very powerful and my overwhelming emotion was anger. There was a moment when we were in the committee room that CNN called the Georgia Senate race for Jon Ossoff, which meant that the Dems now had the Senate, and it was very much like, in the middle of this attack, the American public are saying, ‘OK, we’ve seen enough here, you guys take the wheel for a while.’ They handed the keys to us.” Kaine went up to the Republican senator Lindsey Graham and told him Democrats would not have taken the majority but for Trump’s lies. Graham did not disagree. Kaine said the same thing to the Republican leader, Mitch McConnell, and saw a level of anger in his eyes he had never witnessed before. “The other thing that happened about three hours after we were in the room, the Virginia state police cruisers arrive to help the Capitol police. I went over to [fellow Virginia senator] Mark Warner and said the last time there was an insurrection against the United States, Virginia was leading it. Now here there’s an insurrection that’s being inspired by the president of the United States and Virginia is coming to the rescue of the union. We were both very emotional as we thought about that.” In his book, Kaine, a senator since 2013, acknowledges painful lessons about a country he thought he understood. While he has always been an optimist, he writes, Trump is “a symptom of a national sickness”. Trump is energising and galvanising for Democrats but also brings “a level of dread and tension” to everyday life. Kaine explains: “I was a missionary in Honduras when I was a young man and it was a military dictatorship and it made me be less naive: this authoritarian thing is still real, a lot of people live that way. But even then, when I came back, I still was naive because I thought that would never be something we would see in the United States, the authoritarian impulse. “But it’s Donald Trump and it’s [Nayib] Bukele [of El Salvador] and [Viktor] Orbán [of Hungary] and [Vladimir] Putin [of Russia]. You just go place to place, continent to continent, you’re going to see examples of this. The struggle between the authoritarianism and the democratic impulses is very live right now here and everywhere. That’s the global sickness that I’m talking about. Donald Trump is a symptom. He’s not the cause.” Kaine is one of a small group to have run on a US presidential ticket. His advice to Biden and Kamala Harris: continue to emphasise democracy and freedom, which connect January 6, Russia’s war on Ukraine and rightwing threats to reproductive rights. He also believes they have accomplishments to sell, including the best post-Covid recovery of any major economy. “People aren’t feeling the vibe yet,” Kaine admits, attributing this to a Covid “hangover”. “As I travel around Virginia, this is such a common phrase: ‘I’m doing pretty well but I’m not so sure about three months from now.’ They acknowledge first that economically things are OK but, just around the corner, ‘I’m sure what I’m going to see.’ The Biden-Harris ticket – and I’m on the ticket too because I’m running in 2024 – we just have to sell, sell, sell. The good news is we have a lot to sell.” The alternative, a replay of 2016, putting Trump back in the White House, is too much to bear. “I don’t want to contemplate it. We’re coming up on celebrating our 250th birthday in 2026. I want there to be a vigorous democracy for our kids and grandkids to inherit. And by vigorous, that doesn’t mean just do it the way we did it. Each generation has to decide how to renew these traditions and make them better. “But I don’t view Donald Trump as a guy who’s committed to institutions: one man one vote, free press, independent judiciary, professionalised civil service, civilian control of the military. Donald Trump is committed to himself but he’s not committed to democratic institutions and virtues. He’s done enormous harm to them. “We can wake up from that and, like Job, stick to our principles, become sadder and wiser but still pass the test that is before us. But he will do enormous damage to this nation and to others in the world with a second term.”