Gov. Terry Branstad (R) signed off Tuesday on Iowa’s new Congressional map, which downsizes the number of House districts in the Hawkeye State to four seats.

Created by a nonpartisan redistricting commission, the new map sailed through both legislative chambers with virtually no opposition — an anomaly compared with many other states, where lawmakers often spend months wrangling over the new lines in a distinctly partisan manner.

“It is truly a nonpartisan approach,” Branstad said just before signing the new map into law. “I think we can have some pride that Iowa has a reapportionment system that is fair.”

The map eliminates one district and essentially divides the state into quadrants this cycle.

Two districts lump together two incumbents: GOP Reps. Steve King and Tom Latham are in the northwestern district, and Democratic Reps. Dave Loebsack and Bruce Braley are in the new northeastern district. But Latham and Loebsack recently announced that they will forgo challenging their party colleagues in favor of other plans.

Instead of running against King in the new 4th district, Latham will challenge Rep. Leonard Boswell (D) in the 3rd district, which covers the southwestern corner of the state and includes the city of Des Moines.

Loebsack will run in the 2nd district, which includes Iowa’s southeast quadrant, instead of challenging his colleague Braley, who will run in the new 1st district, which covers the state’s northeast corner.

Meanwhile, Christie Vilsack, the wife of former Gov. Tom Vilsack (D), has indicated that she will likely challenge King in the 4th district.

When questioned about Vilsack’s bid, Branstad told reporters that he thought Iowa’s former first lady would be better off in the eastern part of the state instead of challenging King.

“I think in southeast Iowa, she would be a pretty formidable candidate where she grew up,” Branstad said. “I think in northwest Iowa, she’ll be a fish out of water. She’s never lived in northwest Iowa and it’s a heavily Republican area.”