Answer:
Reagan's support for Nicaraguan Contras was damaging to his image since the money used to fund the contras was earned through the illegal sales of US arms to Iran.
Step-by-step explanation:
During the 1980s Iran was part of a strict Embargo and sanctions, mostly by the United States and it's western Allies.
However, it was revealed that some in the Reagan Administration were illegally supplying the Iranian government with US weapons. The money earned through these sales was then being use to fund the Nicaraguan Contras. These were US-backed rebels in South America who were fighting America's proxy war.
The revelation was very damaging for Reagan's image as many Americans did not even know how close the US was with both Iran and the illegal rebels in Nicaragua.