In the May 2, 2011 edition of The Nation, John Nichols explains that not all Democrats cowered after being called "socialists." His article features this vignette regarding Harry Truman:

[C]onservative Republicans, led by Ohio Senator Robert Taft, announced in 1950 that their campaign slogan in that year’s Congressional elections would be “Liberty Against Socialism.” They then produced an addendum to their national platform, much of which was devoted to a McCarthyite rant charging that Truman’s Fair Deal “is dictated by a small but powerful group of persons who believe in socialism, who have no concept of the true foundation of American progress, and whose proposals are wholly out of accord with the true interests and real wishes of the workers, farmers and businessmen.” Truman fought back, reminding Republicans that his policies were outlined in the 1948 Democratic platform, which had proven to be wildly popular with the electorate. “If our program was dictated, as the Republicans say, it was dictated at the polls in November 1948. It was dictated by a ‘small but powerful group’ of 24 million voters,” said the president, who added, “I think they knew more than the Republican National Committee about the real wishes of the workers, farmers and businessmen.” Truman did not cower at the mention of the word “socialism,” which in those days was distinguished in the minds of most Americans from Soviet Stalinism, with which the president—a mean cold warrior—was wrangling. Nor did Truman, who counted among his essential allies trade unionists like David Dubinsky, Jacob Potofsky and Walter Reuther, all of whom had been connected with socialist causes and in many cases the Socialist Party of Eugene V. Debs and Norman Thomas, rave about the evils of social democracy. Rather, he joked that “Out of the great progress of this country, out of our great advances in achieving a better life for all, out of our rise to world leadership, the Republican leaders have learned nothing. Confronted by the great record of this country, and the tremendous promise of its future, all they do is croak, ‘socialism.’” Savvy Republicans moved to abandon the campaign.