Iran's Assembly of Experts, made up mostly of elderly clerics, has not mattered much for years. The body's main task is choosing Iran's supreme leader, but that job has not come vacant since 1989.

This time it is different. Given the ailing health of Supreme Leader Ayatollah Ali Khamenei, 76, the Assembly to be elected on Feb. 26 for an eight-year term is likely to pick his successor, charting the course of the country for many years to come.

The Supreme Leader is the highest military and judicial authority in the country and has broad powers overseeing other branches of government. Even the president, who is directly elected, has less authority.