World Election

[Lief 🗽]

The Third World bloc would crush the West in any sort of democratic system. A left-wing populist party would win a strong plurality (at least), racking up the vote in South America, Africa and most of Asia.

I think what you would see is large international coalitions. I agree with Vosem, and a world parliament would likely have over a hundred different parties, arranged under the umbrellas of maybe five to ten different coalition parties. Then from those coalition parties you'd have governing coalitions.

List of potential parties:
Development and Justice Coalition: Coalition of populist parties from around the world. Includes many Communist parties.  Strongest in Latin America, Sub-Saharan Africa, India, China. Generally finds little support in non-developing countries. Stated goals include reforming the global economic system to ensure a more equitable distribution of wealth.
Islamic Republican People's Coalition: Moderate Islamist coalition. Centrist economic views, though its base in the Middle East means that it strikes a populist tone. Advocates decentralization on social issues. Strongest in the Islamic world, obviously, especially with middle class Muslims.
Muslim Brotherhood: Hardline Islamist coalition. Cordon sanitaire exists around them. The second party in the Islamic world, especially among the poorer classes. Also some support among ultra-conservative European Muslims, who otherwise don't support the Muslim parties.
Left Front: Pretty self-explanatory. Social democrats, center-left parties, labor parties, left-wing green parties. Despite being center-left and supporting increased worker rights, healthcare, etc., this coalition would generally be pretty conservative when it comes to the existing economic order, i.e. no support of radical wealth redistribution schemes. Most of its support would come from the developed world, though it would also be strong in places with a historically strong Marxist tradition, like Latin America or China.
Coalition for Liberty and Democracy: Your standard centrist/liberal coalition. Very liberal on social issues, supportive of the welfare state, but also staunch defenders of the post-war economic consensus and world economic order. Very little support in the developing world, except among businessmen and the like. Polls high in Europe, USA, Japan, and rich metropolitan areas in developing countries.
Christian Freedom Coalition: Right-wing Christian party. Holds no explicit position on economic issues due to diversity of its members but usually strikes a populist tone. Strongest in the United States, though it also finds support in Latin America and parts of Africa and with some right-wingers in Europe.
International Conservative Union: Conservative populist party. Economically center-right, favors some redistributionary international economic systemic reforms but through "business friendly" means, socially center-right. Includes some agrarian parties. Find most of their strength in the developed world, can also count on decent showings in the non-Islamic Third World.
Alliance for National Determination: Coalition of nationalist parties, federalist parties, some right-wing national parties that support less power for the international government and in extreme cases its abolition entirely. Support is distributed around the world but highest in developed countries.