The truth is that the “socialism” taunt is among the oldest and most discreditable of political chestnuts. It’s been used by conservatives to smear Democratic or progressive policies they don’t like (which is most of them) since the 1930s, more than a decade after the Socialist Party of America last fielded Eugene V. Debs as a presidential candidate.

Let’s take a brief journey down memory lane.

The high-water mark of conservatives’ “socialist” battle cry probably was reached in January 1936, during a remarkable political event at the Mayflower Hotel in Washington, D.C.

This was a gala dinner sponsored by the American Liberty League, a splinter group of wealthy business leaders and old-guard Democrats formed in 1934 in opposition to Franklin Roosevelt and the New Deal.

The glittering star of the Mayflower gala was former New York Gov. Al Smith, who had thrown in his lot with the plutocrats after a distinguished career in which he became an icon of progressive Democratic politics.

As I recounted in my book “The New Deal: A Modern History,” Smith’s apostasy perplexed and unnerved Democrats — after all, FDR, Smith’s successor as governor, had been the man who placed his name in nomination for president at the Democratic convention in 1928 and had bestowed on Smith his nickname, “the happy warrior.”

Whether Smith harbored personal resentments over the rise of a man who had been his protege, or was merely dazzled by his rich new friends, he now was at full-scale war with FDR. It was a delicate moment for the New Deal. FDR’s popularity had fallen to about 50%, a low point.

Business was pushing back against his programs. Roosevelt’s image as a traitor to his class was reinforced by his proposed Revenue Act of 1935, which was openly aimed at the wealthy and was passed largely intact.

An attack on Social Security, enacted in 1935, would become the central theme of the presidential campaign of Republican Alf Landon in 1936. (Landon got shellacked.)

The Liberty League had a solid pedigree from the Wall Street wing of the Democratic Party, including John J. Raskob, a former party chairman and an executive of DuPont.

The league’s board of directors bristled with DuPont family members and executives of big corporations such as General Motors. FDR witheringly described the league to reporters as “an organization that only advocates two or three out of the Ten Commandments…. [They] say you shall love God and then forget your neighbor.”