What was a key issue that united reagan supporters during the election of 1980?

A key issue that united Reagan supporters during the election of 1980 was the Iran Hostage Crisis.

Explanation:

In the presidential election of 1980 the American people elected as president the Republican Ronald Reagan before then president Jimmy Carter.

The elections were marked by the slow recovery of the economic crisis of the mid-70s, whose main effects were a significant rise in inflation and unemployment. At the international level the Soviet invasion of Afghanistan, the fiasco of the Marielitos and the Iran Hostage Crisis also hit Carter hard, especially after the failure of the Eagle Claw Mission to rescue the kidnapped Americans in Tehran. All this benefited Reagan, whose optimism managed to defeat Carter. In fact, most analysts believe that Carter's mistakes in trying to solve the crisis played an important role in his defeat.

The Iranian Hostage Crisis