Onetime presidential candidate and former South Bend, Indiana, mayor Pete Buttigieg has become an important surrogate for Democratic presidential nominee Joe Biden, making the case for him in some interesting and perhaps unexpected venues, including on Fox News. Buttigieg is also promoting his new book at the Boston Book Festival. He spoke with GBH Radio's Craig LeMoult. This transcript has been edited for clarity.

Craig LeMoult: So we've reached the end of yet another fascinating news week. For you, this one began with you playing the part of Vice President Mike Pence, to help Sen. Kamala Harris prepare for their debate. What was that experience like? From your perspective, how did the debate go? Did the vice president say what you practiced him saying?

Mayor Pete Buttigieg: Yeah, there were not a lot of surprises on his side. And the debate, overall, I think was phenomenal for Sen. Harris and for our ticket. You know, the reality is that the VP is very predictable. He will say up is down and the sky is blue, and he'll say it with a straight face. That's one of the reasons he's actually quite difficult to debate when he's out there defending Donald Trump's record. What we saw were a lot of efforts to try to shift the conversation to be about anything but the pandemic and the failed response to it. So I thought she did a great job of always bringing it back to what's actually happening in Americans lives, and that's what this debate and what this election is fundamentally about. I was honored to be part of the process and just really, really admire the way that she she handled the challenging setup, given the vice president's track record of of kind of shifting reality in order to make things look good for Donald Trump.

LeMoult: Your appearances this week on Fox News have been getting a lot of attention, with some video clips going viral of some pretty sharp denunciations of President Trump. What's the goal there? Do you think you can win over Fox News viewers to Joe Biden?

Buttigieg: I think so. Look, the network itself, especially its opinion hosts, are very ideological, but that doesn't mean all of the viewers are. I mean, I think about people in my extended family, people I know who for whatever reason get their information largely from Fox News. That means that if they never even hear my perspective to begin with, that's our fault for not finding a way to get it to them. You know, I've got no illusions about ideological cable media, but I do believe that it's better to at least present what we have to say than to not even go there.

LeMoult: Also this week, Supreme Court justices Thomas and Alito wrote a statement calling for the Supreme Court to revisit the decision that ruled same-sex marriage is a constitutional right. This comes just ahead of the confirmation hearings for Amy Coney Barrett, potentially shifting the court in a direction that could reverse that ruling. That would impact your marriage. What are your thoughts on that?

Buttigieg: Well, it's extremely personal and in a way that the court is personal for all of us, just in different ways. If you have preexisting condition coverage, you stand to lose it, potentially in a matter of weeks as a consequence of the ACA case coming before the court. And I think a lot about the fact that my marriage exists by the grace of a single vote on that Supreme Court. To think that justices from a conservative majority who used to talk a lot about precedents and stability are now, just five years after this became the law of the land, talking about reversing it is really disturbing. It's especially disturbing knowing that our country got better when we took that step forward. The idea that there are people even now, people in positions of power and maybe in a position to follow through, ready to reverse or destroy that progress — it's part of what's at stake in these hearings, but it's part of also what's more broadly at stake in the elections.

LeMoult: Joe Biden has said he's not going to state his position on expanding the Supreme Court until after the election. With Barrett's confirmation basically a sure thing at this point, what do you think Biden should do if he becomes president? You've spoken openly about this in the past, and expanding the court was part of your own platform. What do you think Biden should do?

Buttigieg: So I continue to believe that we're going to need reforms to make the court a less political body. It's not about just getting your way, it's about changing the political temperature of these hearings. This ideological death match that happens every time there's a vacancy is no way for us to approach the highest court in the land. Now when I say that, I'm speaking only for myself, and there are any number of ways to come at that. What I know, though, is that we're in the middle of an election, and I mean literally the middle of an election. It's not just that Election Day is coming up, it's that millions of people have already voted. And Americans believe that they ought to, we ought to have a say in who the next nominee is going to be through this election. And so I think what you're seeing from Biden is a desire not to allow anything to distract from that or to let the Republicans get away with changing the subject when our personal lives, our access to health care, our marriages, and so much more is on the line, not as part of a question about theory or structure, but immediately in a matter of days.

LeMoult: So your new book, which you discussed today at the Boston Book Festival, is called "Trust: America's Best Chance." It talks about the current breakdown of trust and how we have to repair it if we're going to be able to address issues like climate change and racial justice and the pandemic. Right now, no matter who wins this election, there's going to be a significant population of Americans who are not going to trust the winner. How do you think we're going to get over that?

Buttigieg: Yeah, this is a real problem. You know, democracy depends in part on the willingness of those who lose to accept the legitimacy of the process. One of things I write about is the Bush-Gore election. Al Gore had some very legitimate challenges and grievances, but in the end, he stood aside and that was to the benefit of democracy itself. We're not going to see that in a scenario as seems likely where Joe Biden wins, even if he wins big. Donald Trump has already said that any election he doesn't win is by definition illegitimate, which, in addition to just the madness of such a statement, has real consequences. To me, the only way to answer this is with results.

This is a moment in history where there's no choice but to act in innovative, imaginative, bold, serious and pragmatic ways to make Americans lives better off. That, I think, is the best chance to establish the kind of trust we'll need. And then as we proceed, it's time for some structural reforms, too, so that there is less reason to feel jaded about our political system. In an era of gerrymandering and money in politics, and with some U.S. citizens like those in D.C. and Puerto Rico not even being represented in our system, and with an electoral college poised to overrule the vote of the American people in any given election, there are lots of reasons why our system is pretty rickety and would be more trustworthy if we fixed it up. One of things I talk about in the book is, constitutionally our country has amended or improved the Constitution at a pace of roughly once per decade, but we actually have been in a bit of a drought here in the last 50 years.

LeMoult: People are asking basic questions now about the legitimacy of our institutions — the Supreme Court, the presidency, the Senate. Just yesterday, Republican Senator Mike Lee of Utah tweeted "Democracy isn't the objective." Is there a way back, as you see it, to something approaching normalcy?

Buttigieg: I think the next normal is going to be different, but it could be better. This is not just a matter of returning to everything we used to have, especially in terms of our economy before the pandemic and having the same winners and losers, because if we do, we'll have the same weaknesses and eventually we'll have the same problems. It is alarming to see a senator from any party saying this is not a democracy, as though that were a good thing.

I don't know what was on Sen. Lee's mind. I know he's ill with COVID, I don't know if sometimes that leads to people tweeting things they don't mean. Or maybe he's deadly serious. I don't know. But my hope is that we can return to a sense that democracy is fundamental to who we are. And by the way, of course we know this is not like an Athens-style direct democracy — that's a semantic sideshow — but real democracy, the idea that our system is actually going to represent us. The idea that the people are empowered to see to it that our government works for us and not the other way around. That's not just important to us here at home. Our fidelity to that is the bedrock of America's moral authority.