The president of Iran began his re-election campaign facing competition from a career hard-line prosecutor, his own vice president, Tehran’s mayor, a former culture minister and the one-time leader of the country’s sports organization.

Two of the six candidates, all older men, dropped out a few days before the vote this Friday. The remaining contenders are divided evenly between the so-called principlists — hard-line conservatives who assert strict fealty to the principles of Iran’s 1979 Islamic revolution — and the so-called reformists, who are seen as more moderate and flexible.

While no Iranian president has ever been defeated for re-election to a second term, politics can be unpredictable, and the country’s 55 million eligible voters do have real choices when they go to the polls on Friday compared with elections elsewhere in the Middle East.