Robert F. Kennedy Jr.: Vet your potential running mates. We already knew that Jets’ quarterback Aaron Rodgers, supposedly in the running to join RFK Jr. on his longer-than-long-shot presidential bid, embraced some cuckoo conspiracy theories, but it turns out that we didn’t know all of it. According to a CNN report, Rodgers told a network journalist and others that he believed the 2012 mass shooting at Sandy Hook Elementary School was faked and staged, and that the children were “crisis actors.” MORE POLITICS Former Trump insider makes landslide election prediction: ‘Mark my words’ Was Trump su…