She doesn’t tell jokes. She was on the worst Seinfeld episode ever.
Her schtick was to be in sorta frumpy and snarky sidekick roles. I suppose if you like that sort of thing, she had a niche. She's gotten a bit old for that now and her political extremism has her come across not as snarky and sarcastic but as angry, bitter, and generally unappealing. Her role on "24" is awful.