Unseating a party leader in the legislature is always tinged with risk. It suggests everything that members instinctively try to paper over in public: unrest, bickering, second thoughts about the past, alarm about the future. When there's change to be made, they usually prefer to wait until after the session is over and the spotlight has blinked off.

Which explains why almost everyone who pays attention to politics in Iowa was shocked when, in the midst of tough budget negotiations in April, the Senate Republican caucus convened behind closed doors one night and emerged with a new floor leader. The lawmakers chose Mary Lundby, a veteran legislator from the outskirts of Cedar Rapids, stripping power away from Stewart Iverson, a farmer from north-central Iowa who had led them since 1997.

Lundby, 58, is something of a departure from the GOP leadership norm in Iowa. She is from an urban and suburban district in a caucus that has long been dominated by rural members. And she is a moderate in a group that, at least until recently, had a firmly conservative tilt.

Over the past two or three years, says Republican Senator Thurman Gaskill, "there has been a little bit of shifting toward the middle" among GOP senators, but this is not why Lundby's colleagues backed her. Instead, they are counting on her political skills and dogged style to resuscitate their fortunes.

The political crisis grew out of the 2004 election, in which George W. Bush carried Iowa but the GOP lost four net seats in the Senate, producing a 25-25 tie with the Democrats and, for the past two years, a Senate presidency shared between the two parties. "It has been very frustrating," says Republican Senator John Putney, a Lundby supporter. "We looked around and thought perhaps we needed to bring in some new energy, some new creativity, a different kind of savvy." He might have put it another way: The Republicans saw themselves headed for disaster at the polls this year and gambled that different leadership could head it off.

In that regard, Lundby fit the bill. As a member of the state House, she engineered a GOP takeover in 1992. Moreover, her blunt, dogged style is very different from Iverson's. As Lundby puts it, "Mr. Iverson is a gentle, decent person. I have a reputation as a bulldog. I hang on to things that matter, and I don't let go." The one thing Lundby's colleagues hope she doesn't let go of this year is the party's sense of purpose.

If the GOP does hold on to power--even a share of power--Lundby will be viewed as something of a miracle worker. Four Republican senators are retiring, and even Republicans are anticipating a Democratic majority after November. But she has come out fighting: Shortly after defeating Iverson, she announced that she had no intention of letting the Democrats slide by on a huge pay scandal involving executives at a state-funded job services agency. She also pressed her caucus's bottom-line push for tax cuts in negotiations with Democratic Governor Tom Vilsack. "She is," says Putney, "the kind of leader who can take you into battle and bring you home alive."