Bill Maher headlined his first show for HBO 30 years ago, in 1989. Then came his 1993 Comedy Central series Politically Incorrect, which moved to ABC late-night four years later. Until 2001, that is, when Maher made a post-9/11 remark that ABC considered so politically incorrect, the network fired him the following year. But the year after that, Maher was hired by HBO, where Real Time has been presented ever since. And tonight, he and his guests get to opine, comically and otherwise, on the