WASHINGTON (Reuters) - When Israeli Foreign Minister Tzipi Livni recently suggested Ehud Olmert should step aside and let her be prime minister, nobody batted an eye over the fact she is a woman.
Golda Meir laid that debate to rest in Israel nearly 40 years ago.
Britain had Margaret Thatcher, Pakistan had Benazir Bhutto and India had Indira Gandhi. Women hold high office in a dozen countries around the world, in Asia, Europe, Africa and Latin America, from Chancellor Angela Merkel of Germany to President Gloria Macapagal Arroyo of the Philippines.
So why has the United States, where Sen. Hillary Rodham Clinton is a leading contender for the Democratic presidential nomination, never elected a woman to the White House?
"The rules of the game are set up to the advantage of the dominant majority bloc, which is not just Democrat or Republican but is wealthy white males," said Andrew Reynolds, a professor at the University of North Carolina.
Women have tended to have two main pathways to high office, he said. The first is dynastic, which has been the route in developing countries for many women, like Gandhi and Bhutto, who were daughters of prime ministers.
The second pathway is seen in wealthier democracies, where more women pursue careers and political positions that act as a springboard to higher office.
"You get more and more women in parliament and then you get more and more women in the Cabinet, and then you sort of have this critical mass where it becomes no longer surprising that a woman makes it into being president or prime minister," Reynolds said.
The United States is on the latter track but lags many of its European counterparts. Only 16 percent of lawmakers in the U.S. Congress are women. Compared to countries of similar wealth, one would expect 30 to 50 percent, Reynolds said.
The U.S. political structure is partly responsible. Many parliamentary systems encourage alternative voices by allowing small parties, but the United States fosters a two-party system in which the parties have to appeal to a broader audience.
Women have more difficulty being elected in presidential systems. Historically, some 69 percent of women leaders have been prime ministers with only 31 percent from presidential systems, said Ann Gordon, a political scientist who co-edited the book "Anticipating Madame President."
It's a piece of the puzzle, she said, but she sees greater challenges.
"The single biggest obstacle in this country is that voters are uncomfortable with the idea of a woman who is commander in chief," Gordon said. "That's due to gender stereotypes."
Susan Carroll, a senior scholar at the Center for American Women and Politics, said women seeking the presidency still had to address the perception that they were less able than men to deal with military issues and international crises.
Clinton, a New York Democrat, has tried to address the issue by sitting on the Senate Armed Services Committee and taking a strong stance on terrorism during debates, Carroll said.
It also may be a factor in Clinton's refusal to apologize for her Iraq war vote, an issue that has caused her difficulty among many Democratic constituents, Carroll said.
"I don't think Hillary Clinton has the options that other candidates have," she said. "She cannot for a moment appear to be weak on defense or admit to any kind of failing like that."
Women also have been hampered by media coverage, which often focuses on their viability as candidates rather than their message. And structural issues have made it difficult for women as well as minorities to pursue the presidency.
"One of the biggest barriers is simply that we haven't had one," Carroll said. "People have to get used to the idea."
Women have been seeking the U.S. presidency since Victoria Clafin Woodhull ran on the Equal Rights Party ticket against Ulysses S. Grant and Horace Greeley in 1872.
Despite the difficulties, Gordon said the United States would eventually elect a woman.
"It's not a question of if but when," she said. "And yeah, I think the time is now."
© Reuters 2007.