McCain is probably on the take with Mexican drug cartels....his open borders extremism makes it easier for them to conduct business in the US
Could be he's getting money directly from them.
But we know he is definitely on the take with the Albanian Mafia, who've replaced the Italian Mafia here in the US in pushing the drugs. The Albanian Mafia were some of his biggest contributors in this last campaign, have consistently supporting him over the last ten years.