Here's the problem with Chris Matthews playing footsie with the idea of running for US senator from Pennsylvania. When I hear him say something nowadays, I often can't help but wonder whether he means it, or is just trying to position himself for a possible run. Take this evening's Hardball, during which Matthews went off on Joe Lieberman, castigating him as a "terrible" running-mate for Al Gore in 2000. Kiki McLean, a senior Clinton advisor, was Chris's guest. She mentioned that she had served as an aide to Lieberman in 2000, and to Gore when he was the Veep candidate...