Florida congressional candidate Mark Davis sells “8647 ” T-shirts and hats on his campaign website — the same numerical shorthand to express discontent over President Donald Trump central to the case against a former FBI director. James Comey was indicted on two felony counts Tuesday , on charges that his Instagram post of seashells arranged as the numbers 8647 constituted a threat on the president. Comey maintains his innocence, but the fact that he could face years in prison for this phoot raises the question of whether Davis and other buyers and sellers of 8647 merchandise could also be charged with threatening the president. “Arrest us all. I dare you,” said Davis, an Air Force veteran who wears his 8647 hat proudly around his predominantly conservative neighborhood. “I am done staying quiet. I’ve got a family, I’ve got kids, and I’m watching this country get dragged through chaos while people are going to sit down and shut up.…