Ebrahim Raisi's record of fierce loyalty to Iran's ruling clerics helped explain why the senior judge had been expected to win Friday's presidential election, a contest the authorities limited almost exclusively to hardline candidates like him.

The win for Raisi, 60, an implacable critic of the West whose political patron is Supreme Leader Ayatollah Ali Khamenei, burnishes his chances of one day succeeding Khamenei at the pinnacle of power, analysts say...