My thoughts:
Press Releases! A good press release literally tells a story, it creates a piece of news. It's not just a list of relevant information. What's the story here? An indy anthology is focused on non-violent, non-imperialist space stories? Newspaper editors don't want to research your project themselves, they want to read your press release and immediately have something that they can lightly edit and publish in their paper/blog. The key thing here is that the editor doesn't need to be the only person reaching out to press -- any of the creators can too. Your short comic might have its own "news worthy" angle. Press releases aren't so bad to write so long as you adopt the mentality of writing the article that you want newspapers to actually print. There are plenty of great Kickstarter press release samples online.
Likewise, the creators should all be doing what you're doing and helping to promote the Kickstarter as much as they can. It's a pricey KS for a comic anthology! I'm certain that a big part of that is that the editor wants to pay the creators fairly, and that's very, very important. The creators can help by coming together as a team and combining social media presence, sales tactics, media and backer contacts, etc. You guys might already be doing this.
Higher level backer rewards: Right now, the reward tiers are set up like pre-sales, which is a key part of making money on KS. But more personal rewards, more contributions from the various authors, and higher ("angel" level) backer tiers are also important. One $1,000 backer is worth more than 40 backers who are just pre-purchasing the book. How can those guys be convinced to pledge? What similar projects have seen success with high backer reward levels, and what were the rewards that proved to be so enticing?
Take a look at programs like Backer Club (which I've used for Kickstarters before and can admit is legitimately full of mid-to-angel level backers): http://backerclub.co/homepage.php -- submitting to things like this can literally do no harm, and can potentially yield a nice bonus sum.
Keep at it. : ) Running a Kickstarter feels like laying siege to a castle sometimes. You guys might not be rushing towards your goal, but $6,000+ after a few days definitely shows that there is definitely a lot of interest out there for your guys' work!