Fischer and Mourdock, however, are different candidates from O'Donnell, Angle and Buck.
Mourdock is a former geologist who ran for office several times before being elected state treasurer in 2006. He's now won two terms in statewide races and endeared himself to the state's most conservative voters after challenging Chrysler's bankruptcy bailout in a case that reached the U.S. Supreme Court. He also survived an onslaught by Lugar, who spent millions on ads attacking him. Democrats contend that his stance on the Chrysler bailout will hurt him in a state with a large force of auto industry workers.
Fischer used her background to her advantage, playing up a "ranch girl" persona." But she scoffs at the idea that she's a political novice.
"Some folks seem to think I came out of nowhere in this race," she said. "I have been a state senator for eight years. But more importantly than that, I've been involved in a number of organizations in the state for 30 years. I'm not an unknown."
Nebraska Gov. Dave Heineman, one of the state's most popular Republicans, calls Fischer "one of the most effective lawmakers we've ever had."
Local Democrats say the party would be foolish to dismiss her, even if she is deeply conservative.
"So many times, I've called her the Michele Bachmann of Nebraska, but she won't say stupid things like Bachmann has," said Democratic Party donor Bud Pettigrew, referring to the former presidential candidate and Minnesota congresswoman.
Pettigrew, who also is a neighbor of Fischer's, adds: "I don't like her ideas, but I'm not going to underestimate her. She's extremely intelligent."
However Fischer and Mourdock fare in November, Republicans say it's a bad season for longtime officeholders.
"If you're an establishment figure, whether it's (former French President Nicolas) Sarkozy or an establishment Republican in Nebraska, you're in trouble," said Alex Castellanos, a Republican consultant.
Associated Press writers Margery Beck in Omaha, Neb., and Grant Schulte in Lincoln, Neb., contributed to this report.
Follow reporter Henry C. Jackson on Twitter (at)hjacksonap
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