Since almost half of the voters don't even bother to vote why don't we get excited about another choice. Ok, not a very good argument since anyone who gets into these types of discussions believes they will indeed vote, but perhaps some of this excitement will rub off on the 50% of adults who don't bother to vote.
An argument I like goes back to the "lesser of two evils" otherwise known as the "evil of two lessers" statement. Just how far to the right are you willing to go - how many compromises are you willing to accept - before saying enough is enough and looking beyond the two parties to place your vote. Some progressive types feel fine with Gore, so be it. But don't avoid Nader (or anyone else) simply because they are not one of the big two candidates. Vote for the candidate that best represents you. We will continue to get these same corporate candidates if we always vote the same way.
The two candidates are really not that far apart on economic issues. Both have tons of money from oil Gore has $500,000 in Occidental Petroleum Corp a company that "...is due to drill a controversial test well in September in a disputed corner of northeast Colombia where U'wa Indians have even threatened to commit mass suicide to defend what they claim as ancestral land rights." (from a Reuters article) Although not necessary I'll mention that Cheney has a $20M golden parachute from Halliburton (an oil company) including vested stocks amounting to over $11M (as of 13 Sep 00 NYTimes p. A17) still with the company.
In fact 66 major corporations have already donated more than $50,000 to both Bush and Gore. For a list (and a fun website) check out Billionaires for Bush (or Gore). The list is in their analysis section.
Yes there are some big social policy differences. The biggest one is the Supreme Court: (From Nina Totenberg on All Things Considered) If Gore is elected: Rehnquest and O'Conner of the Supreme Court probably won't retire. If Bush is elected: they probably will retire and they are already pretty conservative. Truth in advertising though: Stevens who is 80 will probably retire in any case and he is an old line liberal judge, although Bush Sr. appointed Souter who turned out to be a friend to the left (although as a friend of mine pointed George Sr. is kicking himself for that one.) As it stands though Bush is backpedaling from the abortion issue because he knows it's a loser for him.
Meanwhile neither candidate talks about the failed war on drugs, both support seemingly unlimited free trade with China while none for Cuba, and both support some version of an expense missile defense which could be bypassed by a boat (much cheaper than an intercontinental missile) carrying a biological or nuclear weapon into the harbor of a major US city. Both won't sign the nuclear test ban treaty or the (Land)mine ban treaty which has been ratified by over 100 countries.
By giving more support to Nader maybe some of these issues will receive the attention they deserve. It's apparent that he won't get into the debates (since it's proving hard enough to get Bush in them) but all these important issues should not be sacrificed for one or two others - in my humble opinion. Fair-minded people can disagree.
On a more practical note, Nader is on the borderline to receive the necessary 5% of the popular vote to allow the Green Party to receive matching federal funds. If nothing else a vote for Nader now will lay the groundwork for a better discussions in the future.
Also, while I have no evidence for this I like to think the presence of Nader in the race allows moderates and undecided to consider Gore more closely. You'll notice for once no one on the Republican side is accusing Gore of being part of the "loony-left" or "left-wing." The usual Republican insults are no longer effective.
A strong Nader brings attention to the issues ignored by the majored parties, is part of the unification of labor and environmentalists against corporate greed, and lays a foundation for a left-leaning future in even the major parties. If a person doesn't agree with Nader's positions then they shouldn't vote for him, but if they do, how will their positions ever be heard? Check out http://www.votenader.org for more info.