Study Adam Smith and draw your own conclusions. The most famous representative of political liberalism is probably John Stuart Mill. There are lots of Marxist theoretical thinkers. You'll also find huge databases concentrated on Lenin and Stalin . And of course Rosa Luxemburg.
Anarchism has a lot of support on the net, too.
The Populists do represent a rather 'coloured' group. Representatives of the revolutionary Feminists are Clara Zetkin og Alaksandra Kollontaj. Emma Goldmann was both an Anarchist and a Feminist, while Simone de Beauvoir was Existentialist and Feminist. We might also mention Betty Friedan - a feminist sociologist. These are pages giving information about a number of philosophers.