SDUSA opposed the Senator George McGovern's "New Leftist" approach, pointing to the rout suffered in the 1972 presidential election.

SDUSA has included civil rights activists and leaders of labor unions such as Bayard Rustin, Norman Hill and Tom Kahn of the AFL–CIO as well as Sandra Feldman and Rachelle Horowitz of the American Federation of Teachers (AFT).

Internationally, the group supported the dissident Polish labor organization Solidarity and several anti-communist political movements in global hot spots.

[3] SDUSA's politics were criticized by former SPA chairman Michael Harrington, who in 1972 announced that he favored an immediate pull-out of American forces from Vietnam and coined the term "neoconservative".

Even before the 1972 convention, Harrington had resigned as an Honorary Chairperson of the SPA[4] "because he was upset about the group’s failure to enthusiastically support George McGovern and because of its views on the Vietnam War".

[5] In its 1972 Convention, the SPA had two Co-Chairmen, Bayard Rustin and Charles S. Zimmerman of the International Ladies' Garment Workers' Union (ILGWU);[6] and a First National Vice Chairman, James S. Glaser, who were re-elected by acclamation.

The New York Times observed that the Socialist Party had last sponsored Darlington Hoopes as candidate for President in 1956 and who received only 2,121 votes, which were cast in only six states.

[9] Some months after the convention, Harrington resigned his membership in SDUSA and he and some of his supporters from the Coalition Caucus soon formed the Democratic Socialist Organizing Committee (DSOC).

[11] The changing of the name of the SPA to SDUSA and the 1973 formation of DSOC and the SPUSA represented a split in the American socialist movement.

[10] In domestic politics, the SDUSA leadership emphasized the role of the American labor movement in advancing civil rights and economic justice.

Rustin wrote that the rise of automation would reduce the demand for low-skill high-paying jobs, which would jeopardize the position of the urban black working class, particularly in the Northern United States.

[13] SDUSA documents had similar criticisms of the agendas advanced by middle class activists increasing their role in the Democratic Party.

The election of conservative Ronald Reagan was chalked up to the failure of the Democrats to "appeal to their traditional working class constituency".

[26] Following the death of the organization's Notesonline editor Penn Kemble of cancer on October 15, 2005,[27] SDUSA lapsed into a state of organizational hiatus, with no further issues of the online newsletter produced or updates to the group's website made.

[35] In contrast, Harrington's DSOC and DSA criticized Marxism–Leninism, but he opposed many defense-and-diplomatic policies against the Soviet Union and its Eastern Bloc.

[41] SDUSA and allegations that "Trotskyists" subverted Bush's foreign policy have been mentioned by "self-styled" paleoconservatives (conservative opponents of neoconservatism).

[46][47] Author Justin Vaisse considers some SDUSA members "right-wing social democrats",[48] a taunt according to Wattenberg.

The organizer of the AFL–CIO's support for Solidarity, SDUSA's Tom Kahn, criticized Jeane Kirkpatrick's Dictatorships and Double Standards, arguing that democracy should be promoted even in the countries dominated by Soviet Communism.

[50] In 1981, leading Social Democrats and some moderate Republicans wanted to use economic aid to Poland as leverage to expand the freedom of association in 1981, whereas Caspar Weinberger and neoconservative Jeane Kirkpatrick preferred to force the communist government of Poland to default on its international payments so they would lose credibility.

[55] Justin Vaisse listed five SDUSA associates as "second-generation neoconservatives" and "so-called Shachtmanites", including "Penn Kemble, Joshua Muravchik, ... and Bayard Rustin".

On the contrary, Kemble was recruited by a non-Shachtmanite professor, according to Muravchik, who wrote: "Although Shachtman was one of the elder statesmen who occasionally made stirring speeches to us, no YPSL [Young People's Socialist League] of my generation was a Shachtmanite".

'The distinction between liberation and democratization, which requires a strategy and instruments, was an idea never understood by the administration,' he told the New Republic", wrote The Washington Post in Kemble's obituary.

Tracing forward in lineage through me and a few other ex-YPSL's [members of the Young Peoples Socialist League] turned neoconservatives, this happenstance has fueled the accusation that neoconservatism itself, and through it the foreign policy of the Bush administration, are somehow rooted in 'Trotskyism.'

I am more inclined to laugh than to cry over this, but since the myth has traveled so far, let me briefly try once more, as I have done at greater length in the past, to set the record straight.