They exist as a way of pulling people towards issues and as a release valve if the primary party gets too corrupt.
Take the Green Party in Canada. Without it, the remaining left(ish) parties in Canada only have to go a little better than the Conservatives on the environment to get the environmental vote. With the Greens in, they have to at least meet them half-way or they risk further splitting the centre-left.
They also sometimes hold the balance of power. This puts their issue front and centre.
Take the Green Party in Canada. Without it, the remaining left(ish) parties in Canada only have to go a little better than the Conservatives on the environment to get the environmental vote. With the Greens in, they have to at least meet them half-way or they risk further splitting the centre-left.
They also sometimes hold the balance of power. This puts their issue front and centre.