In these examples, he's using it as a subgroup of pot smokers. That is, the image we have of the "loser stoner" who spends all his day baked. The hippie dope-smoker head-in-the-clouds stereotype disconnected from reality. It's hardly a screed against "marijuana users."
The full exchange in the first example is about the people making a mess of the Wisconsin capitol, where I think people did in fact have bongs IIRC:
GROTHMAN: No, of course not. But the people who are staying overnight are largely making a mess of our capitol. That's what you're addressing. Why are we keeping people out of the building? Because we do not want to have so many people there overnight defacing our beautiful capitol. If you would interview all the people who are creating a ruckus, the vast majority who are here today are not police officers or nurses. They're either college students or hangers on -- or unemployed people just looking for somewhere to hang on.
RUSH: Right. The Democrats and the media want you to think it's just a bunch of average, hardworking out of working, valiant teachers, firefighters and so forth, and it's a bunch of slobs. Maggot-infested, dope-smoking, damn it, hell, longhaired, the whole nine yards. You got longhaired, maggot-infested, dope-smoking FM rock 'n' roller types, exactly who they are. Bong pipes, you name it. Now, I'm gonna tell you something: What Governor Walker and other governors around the country are offering public sector unions is beyond generous. It's outlandish, it's irresponsible. Wisconsin bureaucrats ought to be kissing this governor's feet for what he's offering them during these economic times.