In the wake of Bernie Sanders losing the nomination for President for the Democratic Party, I've noted a lot of people complaining that we don't have enough political parties in America. The thing is that despite the fact that we essentially only have two parties, we still do have many ideologies vying for the influence to set government policy. We just use party primaries and conventions to form alliances among political ideologies before the general election, instead of afterwards. Let me try to explain what I mean.
In many other Western democracies, there are several important political parties. An election works out the strength of these parties relative to one another in the government. One party will end up having the most elected officials, but it won't have enough to run the government on its own, so coalitions are formed after the elections with at least one other party so that there are enough votes in the legislature to pass laws. But forming these coalitions means compromising on policy positions so that those two or more parties are in agreement on enough to ally themselves effectively, but this also means that none of them will get to set policy totally on their own terms. The end result is a ruling alliance of a few parties and an opposition alliance of some or all of the rest.
In America, we work out those alliances before the general election, in the primary process. In either of our two major parties there are various groups who have different ideas about what the party should consider most important. These various sets of opinions compete for influence within the party during the primary process based on which kinds of candidates do well in their primaries. Then the official policy positions are decided at the party convention. Often this means that opinions that were important four years ago get muted or that other opinions on what the party should push for rise in importance. The end result is that a coalition of groups within the party sets the ideological goals and tone for the party for the general election in November.
Almost always, when I hear Americans complain that neither of the two parties really speaks for them, what they mean is that the party that actually does care about their pet issues, doesn't care enough. Well, that is worked out in the primary elections and the party conventions. It is easier to get one of the parties to shift its emphasis than it is to get large numbers of voters to embrace a new party. And make no mistake, getting actual policies enacted into law is not as simple as getting any single candidate elected into office. It requires alliances of elected officials who will compromise with one another on similar ideological goals to get laws passed. And those broad alliances are what our current political parties actually are.