Walter F. Mondale - known informally as "Fritz", probably because the F. stood for Frederick - died yesterday at a venerable age but still younger than Jimmy Carter.
Mondale was a consequential figure in American history. He changed the Vice Presidency. For ages the VP was a joke. Alexander Throttlebottom in the Gershwin musical, who could hardly even get in the White House on a tour. The underlying reason for this was that the VP was usually chosen as a ticket-balancer, someone to represent different wings of the party than the presidential nominee. Consequently he was of no use to the president and rarely trusted by him.
After WW2 and the growth of hair-trigger war alerts, it was generally acknowledged that it hadn't been such a good idea to dump Harry Truman into the middle of running a war without having had any idea what was going on, and the idea of the VP as the Emergency Backup President began to take hold, but while it got VPs better-prepared to take over if necessary, it didn't get them respected in the West Wing.
Mondale changed that. In a memo to Carter before taking office, Mondale wrote that the VP should be the President's most valued free-floating advisor, because, unlike anybody else, he can't be summarily fired, so he can be trusted to give his honest opinion. By the same token, though, he should be close to and sympathetic with the President's goals.
And Carter, who was nothing if not an administrator, took this advice. It worked so well that successors did the same thing, and most VPs since then have taken that role. That Kamala Harris would serve that role for Joe Biden, as Biden did for Obama, and that Biden chose her for that purpose, has been taken for granted. That's the world that Mondale made.
One other thing Mondale did. In the debates in his 1984 campaign for President, he said that both he and Reagan would raise taxes. "He won't tell you. I just did." This bold statement has often been credited with losing Mondale the election. So if you wonder, why don't politicians tell the truth?, the answer is here, in what happened after one did.