It's laid out in the 2020 indictment.
Attorney General William Barr said: “The Venezuelan regime, once led by Nicolás Maduro Moros, remains plagued by criminality and corruption. For more than 20 years, Maduro and a number of high-ranking colleagues allegedly conspired with the FARC, causing tons of cocaine to enter and devastate American communities. Today’s announcement is focused on rooting out the extensive corruption within the Venezuelan government – a system constructed and controlled to enrich those at the highest levels of the government. The United States will not allow these corrupt Venezuelan officials to use the U.S. banking system to move their illicit proceeds from South America nor further their criminal schemes.”
U.S. Attorney Geoffrey S. Berman said: “Today we announce criminal charges against Nicolas Maduro for running, together with his top lieutenants, a narco-terrorism partnership with the FARC for the past 20 years. The scope and magnitude of the drug trafficking alleged was made possible only because Maduro and others corrupted the institutions of Venezuela and provided political and military protection for the rampant narco-terrorism crimes described in our charges. As alleged, Maduro and the other defendants expressly intended to flood the United States with cocaine in order to undermine the health and wellbeing of our nation. Maduro very deliberately deployed cocaine as a weapon.
-PJ
My concern with having Maduro soak up coverage here would be the opportunity for the media to drumbeat accusations against Trump while the government engages in one of its endless investigations and tortuous judicial nitpicking.