More to the point, here's the way in which I think it would be fully legitimate to use my words against me if the occasion arose.
I've run for election four times now, and, among other things, have promised to work on getting the gun registry abolished. If I were to sit up in the Commons and give a spirited defence of the firearms, the long gun registry—I don't know if our all-candidates debates have ever been televised in my riding, but probably not, being a rural area—here's Scott Reid saying that he will seek to end the long gun registry. Here's Scott Reid in the House of Commons saying that this is the best idea since sliced bread and that we've got to fight to preserve it.
Why not? It's perfectly legitimate. It's showing that I'm being a hypocrite on an issue. You could do the same thing in print form now anyway, but it's obviously a good deal more effective, and not illegitimately more effective, to juxtapose those two video clips.