He was a liberal with all the party organization, labor, and other liberal interest groups sewn up the minute Ted Kennedy bowed out. The fact his expected major primary rival, John Glenn, ran an awful campaign that utterly imploded tells just what an utterly gargantuan feat Hart had to upset him in the marathon nomination race. The fact Hart was a handful of ill-timed gaffes away from possibly doing so also says what an empty suit, ableit a decent person, Mondale was.
Mondale was labor's man; no doubt about it. The attack against Mondale, in both the primary and the general, was that he was the candidate of "special interests". Mondale never gave the obvious refutation, that being that his support from women, labor, environmentalists, were not "special interests", but MASS CONSTITUENCIES. He made a poor pick for VP; a Governor or Senator from the South would have helped. He came off as pandering at times. And his statement that he would raise taxes to close the deficit was silly; the Democrats have never been really serious about cutting social programs to combat the deficit and no one wants to pay more taxes. None of this would have precluded Reagan's win, but carrying only MN (just barely) and DC was the result of a horrible campaign.