science & politics of reporting protests

Reading this account of a large “Alaskan Women Reject Palin” rally — reminds me of the massive anti-Gulf War protest in San Francisco in the early 1990s. Almost no media coverage for that protest. Almost no media coverage for this one. And yet, apparently the smaller pro-Palin rally did receive media coverage. I get “if it bleeds it leads”, but are there reasons beyond naked bias and politics for these kinds of disparities in coverage of protests?