Thomas, I'm not sure I'd equate the Republican party of Lincoln to the current Democratic party, even roughly. It was a third party, formed by a coalition of disaffected radical Democrats and Whigs in 1854. Eight years later the country elected Lincoln.

yes, Nader can win, in this sense -- the goal is to take %5 of the popular vote, qualifying the Greens for federal matching funds in 2004 and solidifying the party. To win an election will take a coalition larger than any "third party" can muster this time around -- what the shape of that coalition will be, we'll find out when we get there.