On fast-breaking news days, like the past several, this is all I do for a living, so your donations are my income (and honestly, the more donations the more I can afford to make this like a real job, i.e., non-stop activism and reporting).
Look, blogging takes time. And, doing the kind of blog which tries to stay 5 seconds ahead of the news cycle on a consistent basis takes a lot of time. For someone like John especially (given what his "day job" is - consulting/activism) every moment spent blogging is a moment not spent trying to get work/earn money. Over the long run there may be some self-promotion benefit to blogging, but a very small one.
People forget that time spent blogging isn't just time spent avoiding other fun activities, it's also time spent not doing things which further your career, etc.
Anyway, I guess the point is that you shold make sure to hit the tip jars of your favorite bloggers no matter who they are. And, if you're wealthy blog reader you should consider whether it's better to give a grand or two to [your favorite liberal organizations] or a grand or two to [your favorite bloggers]. Not that it's necessarily a choice, but for good or for ill unaffiliated bloggers are an increasingly important part of the trench warfare of the news cycle, and despite the presence of a lot of free ice cream out there on the internets, your favorite blogger would probably able to give more and better blog and feel good about it if a few more bucks were coming in.
And, finally, this is not a plea for me - go give to other people.