It's good to hear my pal Morford is appreciating Boondocks and at least trying to get into Doonesbury. I had the same problem with Doonesbury for years. It's placement on the Editorial page of many papers is telling. I was like isn't it always about Watergate?
The key, I found is to pick up old Doonesbury books in used bookstores, and slowly catch up. They are easily digestable and each are inextricably set in their moment in time. Skewing hypocrisy and harassing the politicos (pardon the redundancy). Whether it's Frank Sinatra or Al Haig or USA Today or (recently) David Geffen, or... okay there really is a LOT on Watergate & Kissinger.
Uncle Duke is a good point of entry, esp. for folks who already have a thing for Hunter S. Thompson. Duke has been ambassador to China, GM of the Redskins, a Zombie in Haiti, and an Enron bagman; versatile, incomprehensible, stoned. If you really want to bone up on the cast history (the strip has been running for 31 years, so it's not surprising if you get a little lost), the website has a section of cast bios. I just realized, he started the strip the year I was born.
Gary Trudeau is really something special. I could go on. But I won't. Here's an interview from '99 in Salon which I haven't read yet. Blogs can be good for bookmarking. :)