An American Airlines representative said Monday that it was investigating Sen. Ted Cruz (R-Texas) after a photograph surfaced of him not wearing a mask on one of its flights.The photo was posted on Twitter Sunday night. It shows Cruz not wearing a mask while holding a cup of coffee. Hosseh Enad, who works for the Democratic Congressional Campaign Committee, posted the photo.Enad shared another photo coupled with a summary of the American Airlines mask policy. He wrote that airline “policy clearly states that masks should be worn on the flight.”A spokeswoman from Cruz’s office claimed that the…