Michele Bachmann says she's not worried that a new Iowa poll puts her fourth among GOP presidential candidates.

But she won a straw poll in the state in August, was born in Iowa and is counting on a strong showing in the January caucuses.

Since the straw poll, the Minnesota congresswoman has struggled in the race, especially after Texas Gov. Rick Perry jumped in. Bachmann once led national public opinion polls, but got only 8 percent support in the new Iowa poll from the Des Moines Register.

Bachmann tells ABC's "This Week" that her campaign is "doing exactly what we need to do." She says she's campaigning heavily in Iowa and isn't worried about "day-to-day snapshots" of the race.

She's not saying whether Iowa is a must-win state.