In 1906, the British House of Commons was engaged in a debate about the native blacks in South Africa. Nearly all the members of Parliament agreed that the disenfranchisement of the blacks was evil. Not so Balfour, who — almost alone — argued against it.
“We have to face the facts,” Lord Balfour said. “Men are not born equal; the white and black races are not born with equal capacities: they are born with different capacities which education cannot and will not change”
Balfour’s racist views were not limited to Africa. In fact, despite his now iconic support for Zionism, he was not exactly a friend to the Jews. In the late 19th century, pogroms targeting Jews in the Pale of Settlement in Russia had led to waves of Jewish flight westward, to England and the United States. This influx of refugees led to an increase in British anti-immigrant racism and outright anti-Semitism. Support for political action against immigrants grew as the English racists demanded immigration control to keep certain immigrants, particularly Jews, out of the country.
“The racists found a sympathetic ear in Balfour. In 1905, while serving as Prime Minister, Balfour presided over the passage of the Aliens Act. This legislation put the first restrictions on immigration into Great Britain, and it was primarily aimed at restricting Jewish immigration. According to historians, Balfour had personally delivered passionate speeches about the imperative to restrict the wave of Jews fleeing the Russian Empire from entering Britain.” [2]
And also:
The most important British anti‐Semite of that age, in terms of his eventual services to Zionism, was the fanatical Jew‐baiter Lord Arthur Balfour. In a parliamentary debate on the immigration issue, Balfour made a speech in which he put forward a case for anti‐Semitism that is all too familiar. He declared: “It would not be to the advantage of the civilisation of the country that there should be an immense body of persons who, by their own action, remained a people apart, and not merely held a religion differing from the vast majority of their fellow‐countrymen, but only intermarried among themselves.”7
(Source.)