//The terms "anti-Semite" or "antisemitism" came by a circuitous route to refer more narrowly to anyone who was hostile or discriminatory towards Jews in particular//
From the same page on Wiki pp. Didn't want you to miss it. Below is the same page but a bit further down. Do read it all , rather than cherry pick a trite line or two to suit your "needs".
//In 1879 the German journalist Wilhelm Marr, in a pamphlet called Der Weg zum Siege des Germanenthums über das Judenthum ("The Way to Victory of Germanicism over Judaism"), began the politicisation of the term by speaking of a struggle between Jews and Germans. He accused them of being liberals, a people without roots who had Judaized Germans beyond salvation. In 1879 Marr's adherents founded the "League for Anti-Semitism"[17] which concerned itself entirely with anti-Jewish political action.
Objections to the usage of the term, such as the obsolete nature of the term Semitic as a racial term and the exclusion of discrimination against non-Jewish Semitic peoples, have been raised since at least the 1930s//