[3] Religious reformism has variously affected (for example) Judaism,[4][5] Christianity[6] and Islam[7] since time immemorial, sometimes occasioning heresies, sectarian schisms and entirely new denominations.
For example, the historical Reform Party of Canada advocated structural changes to government to counter what they believed was the disenfranchisement of Western Canadians.
[12] None of the initial figures that founded modern socialism in the early 19th century, such as the utopian socialists Henri de Saint-Simon, Charles Fourier, and Robert Owen were revolutionary.
[13] In 1875, the Social Democratic Party of Germany (SPD) adopted a Gotha Program that proposed "every lawful means" on a way to a "socialist society" and was criticized by Karl Marx, who considered the communist revolution a required step.
[14][15] While Luxemburg died in the German Revolution, the reformists soon found themselves contending with the Bolsheviks and their satellite communist parties for the support of intellectuals and the working class.
[16] After Joseph Stalin consolidated power in the Soviet Union, the Comintern launched a campaign against the reformist movement by denouncing them as social fascists.
Some of the younger followers of Gaitskell, principally Roy Jenkins, Bill Rodgers and Shirley Williams, left the Labour Party in 1981 to found the Social Democratic Party, but the central objective of the Gaitskellites was eventually achieved by Tony Blair in his successful attempt to rewrite Clause IV in 1995.