Pearson upset conservaDem Geri Huser in 2010 with under 50 percent of the vote in a three way race, and that was as an unknown with an R after her name in a really good GOP year. She won few friends among her leadership to put it mildly, and derailed an anti-choice bill because it wasn't a pure total abortion ban.
Pearson's retirement may actually improve GOP chances in the new version of Altoona-based House District 30, even though the margin gets slightly more Republican. I'd expect other Republican(s) to jump in. Joe Riding, a moderate-ish Altoona city council member, is already in on the Democratic side.
Bleeding Heartland speculates Pearson may be forming a new anti-choice group; my bet is, now that she has even less to lose, she focuses on recruiting primary opponents for impure House Republicans and further monkeywrenching the whole legislative process.
Republican Galen Davis took advantage of a local Democratic in-fight in this District Draws Itself turf (Ottumwa is 82% of a House district) for a fluke 1998 win. He got knocked off by Democrat Mark Tremmel, who left after one term to run for county attorney.
In 2002 Gaskill, the former county auditor, won a close primary and settled in. Republicans looked like they were making a serious 2010 effort with Jane Holody; even Mike Huckabee took an interest. But Gaskill earned a 57% win. Ottumwa trended Republican the last two cycles with Mariannette Miller-Meeks on the ballot, Republican enough for the fluke 2010 election of Senator Mark "Chickenman" Chelgren. But with MMM not running, I expect Wapello County to trend blue.
Old Senate District 2 was the scene of an epic primary in 2004 as relative moderate Dave Mulder knocked off the state's leading queer-baiter of the era, Ken Veenstra. Mulder stepped down after one term, semi-voluntarily (another epic primary was likely), and Feenstra moved from the county courthouse to the Senate with no opponent in either the primary OR the general. That's likely again this time, which I guess is good; one less race to boost Republican turnout.