Well, the problem there is that the Republicans 100 years ago were a totally different party, as were the Democrats. I wouldn't want most of the "real" Democrats from 1900, when the party still had a strong southern segregationist wing. The nature of the two parties had shifted dramatically by WWII, and especially by the Reagan years. We run the risk of ending up in a "no true Scotsman" argument if we don't recognize the transient nature of terminolgy.