Final answer:
The Iranian Hostage Crisis significantly damaged Carter's presidency due to its prolonged duration and failed rescue mission.
Explanation:
The issue that seriously hurt Carter's presidency was the Iranian Hostage Crisis. The crisis began in November 1979 when revolutionaries in Iran stormed the American embassy in Tehran and took fifty-two Americans hostage.
Carter's attempts to resolve the crisis, including a failed rescue mission, led to a decline in his popularity as the situation dragged on without a resolution.
The prolonged crisis and failed rescue mission compounded with other challenges, contributing to the decline of Carter's presidency.
Learn more about Carter's presidency and the Iranian Hostage Crisis here:
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