Gauge your readers and don't abuse your readership. Do not post your political views on a blog that your readers subscribe to receive technical information. They don't talk about politics on SportsCenter on ESPN, and they don't toss in a shout-out for their favorite candidate while giving the local weather on The Weather Channel.
If you read my blog, you read it because I have written about XML, ASP.NET, web services, WSE, BizTalk, and other geeky things. You don't read my blog so that once every 4 years I can dump my political rants upon my unsuspecting readers.
I am not one of those types of people who feels compelled to police the main feed on weblogs.asp.net, who routinely criticizes people on newsgroups and forums for not staying "on topic." In fact, it is the occasional off-topic post that makes many blogs even more interesting.
If you want me to lose respect for you, post your policitcal views. Worse, post something with absolutely no substance, just "Vote for candidate_here". Worst of all, call the other candidate a "moron", "idiot", or some other name that signals that you have absolutely nothing to offer other than playground namecalling. If you want me to lose respect for you quickly, post something about your policitcal views in your blog. Worse, post something about the candidate you don't like and back it up with nothing more than uneducated emotional tirades.
At least have the guts to put such posts in a category or in another feed so that I can read the tech stuff I am interested in separately from the political blather you are now a self-proclaimed expert on.