Within the varied interests of the capitalist class in the last two centuries there have been political parties that tried to break the monopoly of the dominant two-party system. In 1848, the Free Soil Party, the first major third party won 5% of the vote. The Republican Party quickly absorbed it because Abraham Lincoln after all became the champion of the anti-slave movement and the Civil War obviated the need for the Free Soil Party. In 1892, the Populist Party, which derived much of inspiration from Jeffersonian democracy, finally merged with the Democrat Party at the turn of the century. This was during the Gilded Age when the very rich were enjoying institutional hegemony and it was clear that both Republican and Democrat parties represented the wealthy to the neglect of the rest of citizens at a time that the depression of the 1890s caused immense hardship across America.
The most significant leftist leader in US history was Eugene Debs (1855 –1926) who started out as a union organizer with the Industrial Workers of the World (IWW) and was a Democrat member in his early political caeer in Indiana. A Socialist who had studied the works of Marx among other European Socialists, Debs founded the American Railway Union after the well-known Pullman strike in 1894. To break the strike and prevent future labor-management trouble, President Grover Cleveland used the army and sent Debs to prison. From 1900 until 1920, Debs ran for president, despite harrassment from the state and especially President Wilson who had him convicted in 1918 and sentenced for 10 years under the Espionage Act used to crack down on leftist trade unionists and political activists. Opposing the First World War as one of imperialism backed by capital, Debs noted:
The master class has always declared the wars; the subject class has always fought the battles. The master class has had all to gain and nothing to lose, while the subject class has had nothing to gain and all to lose—especially their lives.To turn your back on the corrupt Republican Party and the corrupt Democratic Party—the gold-dust lackeys of the ruling class—counts for something. It counts still more...to join a minority party that has an ideal, that stands for a principle, and fights for a cause.Debs posed a greater threat for mobilizing workers into a leftist political movement than he did as a presidential candidate. However, the mainstream institutions and especially the press saw him as a threat that must be eliminated from the scene.
A political party that is organized “top-down”, instead of emerging from the grassroots is obviously a reflection of the elites that created it to preserve and expand their interests. When a grassroots movement tries to organize because it feels marginalized in society, the result is that the mainstream quickly co-opts it and de-radicalizes its followers. This happened in the depression of the 1890s, the Great Depression of the 1930s, and the Civil Rights Movement of the 1950s and 1960s.