By the anti-cultural-Marxists (right-wingers, Christian clerical fascists, conservatives, anti-Semites, national-“socialists” etc.) Karl Marx, the greatest thinker of the millennium, is “discredited” as “Jewish father of communism”, but the truth is reversed for 180 degrees; Marx exposed the formality of anti-Semitic critique in his time and displayed the essence of this problem in his article “Parliamentary Debates — The Clergy and the Struggle for the Ten-Hour Day — Starvation” (February 25, 1853):
The exclusion of Jews from the House of Commons, after the spirit of usury has so long presided in the British Parliament, is unquestionably an absurd anomaly, the more so as they have already become eligible to all the civil offices of the community.
The anti-cultural-Marxists, in addition, claim that Marx used the term “holocaust” (of course, their conscience as human beings and social scientists is dead so rather they would discuss about the “holocaust” in the texts of Marx than about the actual holocaust under the capitalism due to which, 15 millions people starve to death every year or about the exterminated 100 million native Americans in the period since 1492 till 1890). This is also their construction for the sake of discredit of Marx’s personality and his social science.
First, the date of this made-up quote is wrong. There is no article dated “April 16, 1856”. The part of this made-up quote: “The classes and the races too weak to master the new conditions of life must give way…” originates from the article “Forced emigration” which was written on March 4, 1853.
Here is this “sentence” in its entire context so from it you can understand that the word “must” does not imply politically administered disappearance of these classes and races, but they must give way because of the application of the modern science based on the capitalistic mode of production:
I share neither in the opinions of Ricardo, who regards ‘Net-Revenue’ as the Moloch to whom entire populations must be sacrificed, without even so much as complaint, nor in the opinion of Sismondi, who, in his hypochondriacal philanthropy, would forcibly retain the superannuated methods of agriculture and proscribe science from industry, as Plato expelled poets from his Republic. Society is undergoing a silent revolution, which must be submitted to, and which takes no more notice of the human existences it breaks down than an earthquake regards the houses it subverts. The classes and the races, too weak to master the new conditions of life, must give way. But can there be anything more puerile, more short-sighted, than the views of those Economists who believe in all earnest that this woeful transitory state means nothing but adapting society to the acquisitive propensities of capitalists, both landlords and money-lords? In Great Britain the working of that process is most transparent. The application of modern science to production clears the land of its inhabitants, but it concentrates people in manufacturing towns.
The second “sentence” from the made-up quote which states: “They must perish in the revolutionary Holocaust” can’t be found in any Marx’s article and the term “holocaust” can’t be found anywhere in the collected Marx-Engels works. Simply, it’s a fabrication of these anti-cultural-Marxists who think that everyone else is stupid (such blockheads like them who quote unread works) so they can be mislead to accredit in this slander directed against Marx. However, there are people who in every instant can check the authenticity of every quote from Marx’s or Engels’ work because these people have at their disposal all the works of these thinkers in 46 volumes (Serbian-Croatian edition, Prosveta, Beograd).
Actually, the “sentence” “they must perish in the revolutionary Holocaust” with the added term “holocaust” is assumed from Engels’ article “The Magyar Struggle” (January 13, 1849) which exactly states:
Alle andern großen und kleinen Stämme und Völker haben zunächst die Mission, im revolutionären Weltsturm unterzugehen. Daher sind sie jetzt kontrerevolutionär.
However, this Marx-Engels’ statement (and the statement itself suggests that by the time adverbs: “zunächst” and “jetzt” meaning “for now” and “now”), as many other statements of theirs, normally, evolved. In 1881 Marx wrote a letter to Vera Zasulich, an important Russian follower, in which he argues that a socialism in Russia was possible through an alternative pathway. A version of socialism in Russia based on the “archaic” commune can take advantage of the developments in technology and social organization created by advanced capitalism. It is not necessary for Russian society to go throughout the several-centuries long process of agricultural and technological modernization that England underwent; rather, Russia can simply adopt the modern technologies now available.
 A non-Marxist biographer called Marx a “towering, learned, and extraordinarily gifted man” (Padover 1978: xvi). Martin Bronfenbrenner deemed Marx “the greatest social scientist of all times” (1967: 624). In 1999, a BBC online survey picked Marx as the top thinker of the millennium, ahead of Albert Einstein (also a socialist), Isaac Newton, Charles Darwin, Thomas Aquinas, Stephen Hawking, Immanuel Kant, René Descartes, James Kirk Maxwell, and Friedrich Nietzsche. In a 2005 public opinion poll in Britain, Marx was chosen as the world’s greatest philosopher.
 http://www.mlwerke.de/me/me06/me06_165.htm In English: “All the other large and small nationalities and peoples are destined to perish before long in the revolutionary world storm. For that reason they are now counter-revolutionary.”