President Obama will spend three days in Iowa next week, his campaign announced Tuesday, a major investment of time for the president in a key swing state.

Obama will start in Council Bluffs, just over the state line from Omaha, on Monday, before campaigning in Boone, Oskaloosa, Marshalltown and Waterloo. On Wednesday, he'll be joined by first lady Michelle ObamaMichelle LeVaughn Robinson ObamaMichelle Obama celebrates success of ‘Black Panther’ How textbooks shape teachers — not just their students Michelle Obama dedicates Valentine's Day playlist to Barack Obama MORE for campaign events in Dubuque and Davenport, two major troves of Democratic voters along the Mississippi River in eastern Iowa.

That Obama is spending three full days in Iowa — and bringing in his wife to help him — shows how concerned the campaign is about holding onto the state that launched his presidential career and gave him a nine-point edge in 2008's general election.

While there has been little recent public polling of the state, three of the last four public polls of Iowa dating back to late May show Obama and Mitt Romney in a statistical dead heat in the state, which appears to be Romney's best chance by far of winning a state that's leaned Democratic in recent years.

This post was updated at 8:20 p.m.