In what one analyst called a "bonanza" for Republicans nationally, North Carolina's GOP lawmakers proposed new voting districts Friday that would make it significantly harder for four Democratic congressmen to keep their seats.

The proposed map would threaten Democratic Reps. Larry Kissell in the 8th District, Heath Shuler in the 11th and Brad Miller in the 13th. Democrat Mike McIntyre's 7th District also would grow more Republican.

"In the national context, Republicans don't have any more North Carolinas," said David Wasserman, an analyst with the Washington-based Cook Political Report. "This is their gem, their ace ... This is a Republican redistricting bonanza."

Democrats now hold a 7-6 edge in the state's delegation. The new map could put up to four more seats in Republican hands.

Republicans downplayed any partisan advantage.

"Here you have fair and legal districts that are competitive," said GOP Sen. Bob Rucho of Matthews, who chairs the Senate Redistricting Committee.

Lawmakers are scheduled to vote on the plan - along with still-unreleased legislative districts - in a special session that starts July 25. Any plan would have to be approved by the U.S. Justice Department or a federal court.

Democratic Gov. Bev Perdue, who already has vetoed 15 bills passed by the GOP-led General Assembly, cannot veto redistricting bills.

The congressional plan puts more Democratic voters into three Democratically held districts but takes away many Democrats from three others.

Among the changes:

It takes about 37,000 African-Americans from Kissell's 8th District, in part by moving many Mecklenburg County precincts to Democrat Mel Watt's district. It adds part of Democratic-leaning Robeson County but also Republican-leaning portions of Rowan, Davidson and Randolph counties.

"It is unfortunate that the legislature has gerrymandered the Congressional maps," Kissell said in a statement. "But ... I plan to seek re-election, return to Congress and continue the fight."

The 12th District, which Watt represents, would get more African-American voters. So would the state's other majority-minority district, the 1st in the northeast.

That district, represented by Democratic Rep. G.K. Butterfield, would dip into Raleigh, splitting Wake County into four congressional districts.

Republican Rep. Sue Myrick's 9th District would gain southern Iredell in a district that includes parts of Mecklenburg and Union counties. She would lose Gaston County to the 10th District, represented by Republican Patrick McHenry.

McHenry would pick up the city of Asheville, siphoning Democratic voters from Shuler in the 11th District. Shuler's 11th District would pick up Republican-leaning voters in Burke, Avery, Mitchell and Caldwell counties.

"The way (districts) were drawn in 2000 seemed awfully gerrymandered," said state GOP Chairman Robin Hayes. "So if they went from gerrymandered to fair and legal there would be a potential for a pick-up of Republican seats."

State Democratic Chairman David Parker had a different view.

"Any fifth-grader can see that this map is nothing more than a Republican attempt to re-segregate the South," he said in a statement. "Republicans have clearly packed African Americans in the 1st and 12th districts ... These maps are simply ridiculous."

'Turnabout is fair play'

The most vulnerable Democrat would be Brad Miller of the 13th District.

Democratic registration in the district would drop from 51 percent to 41 percent, while Republican registration would increase from 26 percent to 37 percent. The district would lose 130,000 African-American voters.

"Turnabout is fair play," said analyst John Davis of Raleigh. "When (Miller) chaired the N.C. Senate reapportionment committee 10 years ago, he drew himself a congressional district he could not lose. Now he's in a district he cannot win."

Watt and Butterfield would get more Democratic voters, and so would Democratic Rep. David Price of Chapel Hill. But Price's new 4th District, now centered in the Triangle, would snake through Lee, Harnett and Cumberland counties. Along the way, it would pick up Democratic voters from Republican Rep. Renee Ellmers.

"While I am sad to see different areas lost ... (in) the new map, I am also excited to bring my service and dedication to the new constituents that may be added," Ellmers said in a statement.

Ellmers was the only GOP pick-up in North Carolina last year, even as Republicans were winning enough seats across the country to take back the U.S. House. That's one reason there could be so many vulnerable Democrats in 2012.

"So many Democrats survived 2010 in North Carolina that there were a lot of targets," said Wasserman of the Cook Report. "(Republicans) can't be nearly as aggressive in other states."

Ilario Pantano, a Republican who challenged McIntyre in 2010 and plans to run again, said he was prepared to run under any configuration of the 7th District.

"At the end of the day, the shape of a district is a lot of political inside baseball," he said.

Lynn Bonner and Michael Biesecker of the (Raleigh) News & Observer contributed.