Japan’s ruling party elected its first woman leader. She may not become prime minister

Sanae Takaichi won the Liberal Democratic Party leadership in a run-off against Shinjiro Koizumi on October 4.

Sanae Takaichi, the recently elected leader of Japan’s Liberal Democratic Party, is facing an uphill battle to become the country’s first female prime minister, after the LDP’s ruling coalition partner quit the 26-year partnership, throwing Japanese politics into chaos.

A staunch nationalist who models herself on Margaret Thatcher, Ms. Takaichi won the LDP leadership in a run-off against Shinjiro Koizumi on October 4. It was expected parliament would endorse her as successor to outgoing Prime Minister Shigeru Ishiba in a now-postponed vote this Wednesday.

With the ruling LDP-Komeito coalition not holding a majority in either house of parliament, there were already questio