A character from a show, where everybody knows your name. Also, a thing the current president is driving us off, with no shame

A declaration by a famous sleuth. A type of particle. A school where one probably learned to spell this.

Add a letter to my end, would you? I belong to the lineage of a mister; Donald is his name, childish his moniker. He does not reign, no, he does not rule, But he uses lyrics like a tool. Once you know, remove the last; your hand I cover.

I’m a pit that’s not in the ground, on your body, in pairs I’m found. I’m a host for hair and lint, but may raise a stink that makes others squint.

I have legs but never walk, a back but never complain. I host tired humans, lonely pigeons, and forgotten gum. I hear secrets, watch joggers suffer, and get blamed for cold seats. In parks and courts I quietly sit - What am I, besides emotionally supportive furniture?