I find that third party activists tend to see things differently from people who favor the name-brand political parties.
On the economy, both parties will continue to sell favors to the highest bidder. The highest bidders will be the same people they've always been. The Republicans sell them favors via changes to the tax code. (Then they advertise that they have made these huge tax cuts that don't add up to much when they get down to the average taxpayer.) The Democrats sell them more direct favors in terms of spending and incentives.
On national security, aside from rhetoric and the occasional meatball who runs around invading random countries who haven't actually attacked us, the differences tend to be measured in percentage point funding differences rather than real differences in substance. Both parties contributed to the "containment" policy that eventually won the Cold War. Both parties helped fight the great wars of the 20th century.
Iraq is important, but the most important aspect in this election is where we go from here. Bush's policy (promising to use our soldiers to act as a buffer between sides in a civil war for at least a decade), is distinct from the way that I see things happening under either McCain or Clinton.
I see McCain using our continued involvement to pressure real political reform inside Iraq. I'm not sure that policy will work at this point, but there's a good argument that it is worth a try. I see Clinton starting to withdraw troops and using the withdrawal schedule to try to pressure for real political reform inside Iraq. (ie, I see her offering to slow the withdrawal schedule if benchmarks are met within Iraq.) I'm not sure that policy works either, but at least we have a chance to get our military ready for the next time somebody actually does attack us.
At this point, more than half of the Iraq legislature has signed a letter asking us to leave. The ministers and government officials who are asking us to stay are representing a minority opinion.
Petraeus did a great job giving the politicians another chance to rescue the current situation. Unfortunately, I see the administration and the hawks too busy crowing about the reduction in violence, and not busy enough trying to fix the political situation so that it doesn't flare back up again in a few months. We seem determined to blow yet another opportunity.