"Wow, word seems to be coming out that the Obama FBI “SPIED ON THE TRUMP CAMPAIGN WITH AN EMBEDDED INFORMANT.” Andrew McCarthy says, “There’s probably no doubt that they had at least one confidential informant in the campaign.” If so, this is bigger than Watergate!" Trump said in a Twitter message.
Trump's tweet refers to an article penned by McCarthy and published by National Review on Saturday.
Simpson has said that person was Trump campaign aide George Papadopoulos, but McCarthy believes it was someone else, who the FBI planted with the campaign, not an aide who cooperated with the investigation willingly.
Fusion GPS is the firm hired by a Republican, and then the Democratic National Committee to research Trump's alleged ties to Russia.