That's not a Churchill quote, despite popular use. There's no evidence he ever said it. The quote originated with Francois Guizot:
"Not to be a republican at twenty is proof of want of heart; to be one at thirty is proof of want of head."
http://books.google.com/books?id=uIRi0B ... &ct=resultIt wouldn't make sense for it to be a Churchill quote, either, since he was in the conservative party at age 25 and then switched to the liberal party(which doesn't quite equate to liberalism as we define it today, but was still more liberal than the conservative party of that day) later on in his political career. He switched back to the conservative party later, but in his youth he was arguably more conservative than in the middle of his life.
