Were 19th century democratic socialists the same as social democrats?

I think that the two terms ("democratic socialist" and "social democrat") were pretty much used interchangeably when Malatesta was writing. When Marx was writing, the term was not used by Marxists until the 1870s/1880s -- in France, in the 1830s/1840s it referred to the likes of Louis Blanc and other Jacobin-socialists.

Groups taking over labels used by others was a common feature of the time -- "collectivists" was used in the IWMA by the Federalist-wing but in the early 1880s it started to be used by the Marxist-wing of the French socialist movement (anarchists preferring communists by then).

Names and terms change due to time and place. In the 20s and 30s groups calling themselves left communists had a strong chance of being Trots as they were referring to Trotsky's Left Opposition in the fights with Stalin.

In the UK, most Labour Party and adjacents would use Democratic Socialist to draw some distance between them and the Soviet Union and its supporters. Nowadays, I've noticed that within the Labour Party there's a new distinction, Labour's left use Democratic Socialist and their right wing are using Social Democrat, so I guess there's a distinction there if you look hard enough.

I mean, wasn't it only until the 19th century that the definitive split between social democracy and revolutionary marxism occurred? I mean, for a while the Bakuninist faction in the International was called the International Alliance of Socialist Democracy: https://www.marxists.org/history/international/iwma/documents/1868/iasd-program.htm

I think the programme of the old Bakuninist IASD was probably quite a way from what either "democratic socialism" or "social democracy" might suggest today though.

In the 19th Century you had different factions in the social democratic movement eg in Russia with the Bolshevik faction in Russian Democratic Party who proved serious about carrying out the full "social democratic" program involving wide scale nationalisation of industries, rationing etc but covered up this program with talk about supporting workers control and land for the peasants etc. Particularly in Lenin's Pamphlet "State & Revolution" full of ultra democratic workers' state talk. They carried out their coup in October 1917 and set up a dictatorship to carry it out. After taking power and with moves to set up the 3rd International - they renamed themselves as the Communist Party. The menshevik faction of RSDLP supported bourgeois democatic/parliamentary regime and not in favour and not capable of carrying out key aspects of the social democatic program.
Today globally those parties which use the social democratic or Labour Party labels are all heavily involved in pursuing the neo liberal agenda and as are today's corporate bureaucratic unions which have power in them - also these parties and corporate unions are interwoven with the corporate set up/deep state/corporate media etc and its agendas by innumerable threads.

Also see "From Bureaucratic Corporate unions to Grass Roots Controlled Direct Action Unionism: Perspectives and Activity for Australia Today" on Libcom.org and on www.rebelworker.org RW Dec. 2023 - Jan. 2024 for a discussion of Corporate Unionism and its Relationship with the neo-liberal agenda and the Australian Labor Party

When Marx penned his words directly below there were no political parties formally titled democratic socialist or social democratic. He was describing a general tendency. It is a tendency that encompasses a broad political spectrum, of left and right, including tendencies published here that claim the mantle of anarchism, socialism and communism.

The peculiar character of social-democracy is epitomised in the fact that democratic-republican institutions are demanded as a means, not of doing away with two extremes, capital and wage labour, but of weakening their antagonism and transforming it into harmony. However different the means proposed for the attainment of this end may be, however much it may be trimmed with more or less revolutionary notions, the content remains the same. This content is the transformation of society in a democratic way, but a transformation within the bounds of the petty bourgeoisie. Only one must not get the narrow-minded notion that the petty bourgeoisie, on principle, wishes to enforce an egoistic class interest. Rather, it believes that the special conditions of its emancipation are the general conditions within whose frame alone modern society can be saved and the class struggle avoided. Just as little must one imagine that the democratic representatives are indeed all shopkeepers or enthusiastic champions of shopkeepers. According to their education and their individual position they may be as far apart as heaven and earth. What makes them representatives of the petty bourgeoisie is the fact that in their minds they do not get beyond the limits which the latter do not get beyond in life, that they are consequently driven, theoretically, to the same problems and solutions to which material interest and social position drive the latter practically. This is, in general, the relationship between the political and literary representatives of a class and the class they represent.

Marx talks about democratic socialists in some of his writings and criticizes them.

Notably, amongst numerous others, his ' "friend" ' Ferdinand Lassalle, for being a tight arsed "Jew".