Going into the 1984 election, America was happy with Ronald Reagan at the helm of the country, and we were worried about the Russians and their dirty tricks. Realistically, nobody was going to beat Reagan at that time. Although Mondale's loss ended up being of epic proportions, he never really stood a chance to actually beat Reagan.
Yes, Walter Mondale's presidential campaign was doomed from the start. The 1980s saw the rise of Ronald Reagan and the return of conservative values for many Americans. Reagan's "morning in America" slogan capitalized on the feelings of malaise and disapproval that many Americans had following the perceived excesses of the 1970s.
Walter Mondale ran knowing that he did not have the support of the majority of American voters. He lost to a beloved entainer who was a household name, despite the fact that he had much more politcal experience than his oppontent did. He was unable to gain enough support and knew this from the begining.
There are times that the people's vote is more about a movement than it is about the person. Mondale had some great ideas. What he did not have was charisma. Also, at the time, people wanted to think that their vote was going towards something more progressive. At a different time in history, he may have been more successful.