By the end of the twentieth century, women could vote in almost every country that held elections at all. A demand once treated as absurd had become ordinary. Equal suffrage was written into the Universal Declaration of Human Rights in 1948, and the UN Convention on the Political Rights of Women of 1952 committed signatories to let women vote and hold office on equal terms. It is worth asking what that victory actually changed, and what it did not.

Uneven victories

Women's suffrage rarely arrived for all women at once. The pattern seen in earlier levels repeats across the world: the vote often reached women of the dominant group first. In Australia, Aboriginal people did not gain the federal vote everywhere until 1962. In the United States, many Black women in the South could not vote in practice until after the Voting Rights Act of 1965. In South Africa, the vote was given in 1930 to white women only, partly to dilute the votes of Black and Coloured men, so that a women's reform first served to strengthen white rule. A full history of suffrage therefore has to ask not only when women won the vote, but which women.

Did women vote differently?

Opponents had predicted disaster and supporters had predicted moral renewal. Neither happened at once. In many countries women's turnout was at first lower than men's, as new voters took time to build the habit. In much of Europe in the decades after the vote, women tended to vote somewhat more conservatively than men, often for religious parties, which seemed to confirm the clerical fear. From around the 1980s this reversed in many democracies, and women began to lean further left than men, a pattern political scientists call the modern gender gap. The lesson is that women never voted as a single bloc. Like men, they divided by class, religion, region and conviction.

Effects on policy

There is good evidence that the vote changed what governments did. A well-known study by the economist Grant Miller found that after American states gave women the vote, legislators quickly raised spending on public health, and child death rates fell, particularly from infectious diseases. Politicians who had ignored sanitation and maternal care began to pay attention when mothers could vote them out.

Votes are not seats

Winning the vote did not bring equal representation. For decades after suffrage, women made up only a few percent of most parliaments. The world's first woman prime minister, Sirimavo Bandaranaike, took office in Ceylon, now Sri Lanka, in 1960. Many countries later adopted gender quotas, either in law or within parties, to speed change. The most striking example is Rwanda, where women have held a majority of seats in the lower house since 2008, after a post-genocide constitution reserved seats for women. Critics of quotas worry that they can produce token members chosen by party bosses; defenders reply that men have long benefited from informal quotas of their own.

How the vote was won

Looking across the whole story, a few patterns stand out. Movements that won combined many tactics: petitions and lobbying alongside marches and, in some places, militancy. They built alliances with other causes, such as temperance, labor and national independence, sometimes at a moral cost. Wars and revolutions often provided the moment, but only where campaigners had already prepared the ground. And in nearly every case those who already held power, men voters and legislators, had to agree to share it. That is perhaps the most hopeful lesson: people can be persuaded to widen the circle of those who count, even against their narrow interest.

The deepest argument was always the simplest. If every person has equal worth, then laws that bind everyone should be made with everyone's consent. Suffragists did not always live up to that principle, and some used it selectively. But it is the principle that eventually won, and it remains the standard by which any exclusion from the vote, of any group, can be judged.

Worked example: South Africa, 1930

South Africa's Women's Enfranchisement Act of 1930 gave the vote to women, but only to white women. The timing was no accident. In the Cape Province, a limited number of Black and Coloured men who met property and education tests had voted alongside white men since the nineteenth century. By adding white women, and not Black women, the government of J. B. M. Hertzog roughly doubled the white electorate and diluted the votes of Black and Coloured men. In 1931 property and literacy tests were removed for white men too, and in 1936 Black voters in the Cape were taken off the common roll entirely.

This case is a warning against telling the history of suffrage as a simple march of progress. The same reform, women's votes, could advance equality in one country and serve racial domination in another. Universal suffrage in South Africa came only in April 1994, when Black women and men queued for hours to vote in the first democratic election. The test of any franchise, then and now, is not whether some new group is included, but whether anyone is still left out.