Answer:
A booming economy.
Step-by-step explanation:
Ronald Reagan re-election in 1984 was one of the biggest victories in the US History, he carried 49 of the 50 states and won the highest number of electoral votes ever.
During the 70s inflation was a major problem and the US faced a deep recession in 1981-1982. Reagan was able to help with a strong economic recovery by passing a corporate tax increase and passed the Tax Equity and Fiscal Responsibility Act of 1982.