Trump made the announcement during the 2020 State of the Union address. Limbaugh, a far-right radio host, had recently been diagnosed with lung cancer.

Limbaugh is notorious for his wide array of conspiracy theories and other debunked claims, including the assertion that nicotine had been proven to not be harmful or addictive. He has also made remarks like that Columbus saved the Indians from themselves, that Obama was paying lesbians to become farmers in rural states, and called 12 year old Chelsea Clinton “a dog,” among various other racist remarks.

The New York Times – Rush Limbaugh Awarded Presidential Medal of Freedom at State of the Union
USA Today – Medal of Freedom: What is it and why did Trump award it to Rush Limbaugh during State of the Union?
Snopes – Rush Limbaugh Said … What?
Vanity Fair – Rush Limbaugh’s 10 Dumbest Remarks