By Chris MatthewsLet me finish tonight with the power of video. The days are over, gone, kaput, when you can say something and hope people will forget about it.You say "macaca" at a picnic somewhere and you're finished politically. That tape of yours never dies. It lives on and on and on and on - even to the end of time.Ask George Allen, the former senator from Virginia.You say, as Arlen Specter, did that you changed parties to save your seat in the Senate and those witnessed words endure even as your Senate career begins to fizzle.You're Richard Blumenthal and you say you went to Vietnam and you never did and that tape never dies.Rand Paul? You can blame the interviewer. But it's your words, witnessed on tape, that haunt you. That tape of you talking to the Louisville Courier-Journal editorial board, that tape of you not coming across with Rachel Maddow. Those tapes are going to survive you buckling to political practicality. Your opponent is going to throw them back without pity.No, they're not all lethal.Rand Paul can prevail if he accepts the historic merit of the civil rights bill.Arlen Specter might have prevailed if he'd presented the voter with some compelling reason "Pennsylvania" had for giving him another term.But sometimes, you say something and the only way to get past it is to admit something really bad about yourself, something that most voters might never accept.That "macaca" line is one. It's a term used to mock black people, to reduce them to something less than human.That bogus claim of having fought in Vietnam, that's another one. What's changed is this new, man-made custody in which I can now place myself when I speak in public. Because of video we are now the prisoners, forever, of the public moment we enter. It is not a place where you should expose yourself unless you are truly ready to be a person of your word - because your word, once spoken, may raise you up or it may take you down, but now you can never escape it.