Janeane Garofalo

At this summer's Latitude festival in England, American Janeane Garofalo was scheduled for a gig in the comedy tent. She ended up performing for just five minutes before apologising to the audience and attempting to leave the stage. However, the show's MC couldn't be located immediately and she was forced to remain on stage for another couple of embarrassing minutes before he was found. Irish comedian Ed Byrne, pressed into doing an elongated performance, began his routine by asking if he would be receiving Garofalo's fee.

It would be an embarrassing situation for any performer, much less one with 25 years' experience on stage, but it says a lot about Garofalo that she bounced back immediately to receive glowing reviews at the Edinburgh festival, and has no qualms about discussing the incident as her first Irish show looms. "I was bombing, I was doing terribly," she recalls.

"It wasn't the audience's fault, it was my fault. I don't tend to thrive in festival settings during the day and I sort of psyched myself out. The audience looked so nice and expectant and had such sweet young faces that I couldn't bear to disappoint them, so I explained my situation to them and was compelled to deconstruct it. And they stared at me and then I said 'I should probably go'. It seemed like the most polite thing to do. They were in a tent and there was comedy all day so I figured no one would miss me."

Her skin hasn't thickened enough over the years to inure her against those kinds of setbacks. "Not at all. I feel as badly about that as I did when I started out in 1985. I hate it – it embarrasses me to my core." Still, she's emerged from worse experiences than bombing in a show. Over the course of her career, she's been a hate target, having to put up with being insulted on stage and jostled in the street. There have also been death threats and the decapitation of a Janeane Garofalo puppet to stomach.

Although born in New Jersey, Garofalo spent most of her formative years near Houston, Texas. Her brother's collection of comedy albums – George Carlin, Steve Martin and Albert Brooks – made an early impression and after graduating with degrees in American studies and history, she hit the comedy circuit, supporting herself with a number of jobs she hated, including shoes saleswoman, bike courier and moderator on a teen chat-party line.

Being one of few female comedians back in the '80s was never a concern for her, unless she felt she was being treated differently. "There were a lot of club managers and bookers who would say that female or black or Latin comedians weren't as funny or didn't do as well in their clubs. That would bother me, that there would be subcategories in comedy. Cos there was no shortage of unfunny white comics, believe me, but I never heard anyone say that."

She was spotted by Ben Stiller, who invited her onto his TV sketch show, and a further chance meeting saw her land the role of Paula, the acerbic booker behind the scenes on The Larry Sanders Show, a role for which she received two Emmy nominations. Many comics find it hard to make the move from stage to TV, but Garofalo appeared to do it with ease.

"Gary Shandling [star of Larry Sanders] was a stand-up comic and a lot of people on The Ben Stiller Show were from that world so it was an easy transition. That was not the case in a lot of other TV projects I worked on which were not as loose and the environment not as open to improvisation and in a lot of cases not as well written as The Larry Sanders Show. I got lucky with The West Wing – that was incredibly well written and there was certainly no improvisation in that. It's definitely case by case."

She considers herself "primarily a comedian", having begun doing stand-up when she was 19 but not started acting until she was 27. Hollywood came calling in the mid-'90s and she had hits with Reality Bites, The Truth about Cats and Dogs, and The Matchmaker (the last of which saw her filming in Galway, her first and only visit to the land of her grandparents). Soon after, she found her fame as an actress/comedian being outstripped by her notoriety as a celebrity activist. She's too savvy not to realise she was putting herself in the firing line with her outspoken views against George Bush's administration but carried on regardless.

"Being in the entertainment industry doesn't define me; I am still a citizen first and foremost and a tax-paying citizen at that," she says. "There was a time, starting with the stolen election of 2000, where things were so out of hand that it seemed unreasonable not to speak out if given the opportunity."

This meant appearing on right-wing political shows on the Fox Network, where the hosts eschew political debate in favour of shouting down their guests. "It's absurd. It's Rupert Murdoch bullshit and his nefarious agenda is certainly present in other countries too. Yeah, the Fox Network is a joke. I have no idea why I did that, it was clearly a fool's errand, but I didn't know how ridiculous that network was when they invited me on. You can't even parody it, but it's not funny, only tragic."

The resulting threats and abuse didn't help. "Yeah, it's horrible. It makes me sick to my stomach but I was never unaware that I would be mocked. I did not expect the level and the intensity of it, because who could? Why would there have been such a response to pointing out the obvious corruption and dishonesty of a governing body?"

Garofalo says she was never bothered by the fact that her political views could interfere with her burgeoning film career, pointing out: "It's not like I was working with Scorsese."

She did, however, get to share the screen with many other famous Holly­wood activists in Team America: World Police, a satire featuring puppets, from South Park creators, Trey Parker and Matt Stone. "I know of it but I haven't seen it," she says. "I know that my head gets blown off, but on the other hand my puppet shares a scene with the George Clooney puppet, I hear, which I'm thrilled about. The only thing that bothers me about that, besides the fact I think those guys [Parker and Stone] are kinda douchebags, is that I ran into them in the street and I said the least they could do is send me a puppet, seeing as they had blown my puppet's head off. They said they would and even took my address, but never did."

For somebody with such left-leaning views, it was a surprise to see her pop up recently in the right's wet-dream show, 24. "The most right-wing guy from 24 doesn't work there anymore, and he definitely had an agenda, and I certainly did not like that about the show. But I'm not playing myself. If I play an assassin, it doesn't mean I support assassinations."

She's patriotic enough to defend her country when she sees fit, or simply when she recognises that people in glasshouses shouldn't throw stones. "It's very easy to mock American politics, everybody does it, but then I go elsewhere and you see the same bullshit. There's always the same in-fighting whether it's congress or parliament, same sub-par reporting in news outlets around the world, same street-level biases with the people you meet. There are people who are belligerent with their nationalism and some that are much more open-minded. I think people love to point the finger at America and say, 'boy what a pack of dicks' and then I go to other places and I say, 'you got your assholes too, but you don't seem to want to see that'. Or it's just easier to look at other people's assholes. But that's just part of the human condition."

Janeane Garofalo plays Dublin's Olympia on 23 September as part of the Bulmers International Comedy Festival, www.bulmerscomedy.ie