With the state legislature approving new redistricting plans last week along party lines, federal and state courts are Democrats’ last line of defense against a set of maps that could ensure Republican control of the North Carolina congressional delegation — and the General Assembly — for the next decade.

Although no lawsuits have been filed, expect litigation soon. The North Carolina chapter of the NAACP has threatened a suit. Meanwhile, the maps are headed to the U.S. Justice Department and a federal court in Washington, D.C. for preclearance, a requirement under the Voting Rights Act of 1965 meant to curtail disenfranchisement of minority voters.

Barring prolonged federal intervention or an unfavorable ruling from a state court, the maps will be in place for the 2012 election. Analysts predict that will mean a Republican gain of between two to four seats in the congressional delegation. (The current split, out of 13 seats, favors Democrats 7-6.)

At the state level, Republicans would shore up their 16-seat majority in the House and 12-seat majority in the Senate, possibly maintaining (in the Senate) and securing (in the House) veto-proof majorities, according to GOP-leaning consultant John Davis.

“The die is cast. If the courts bless these plans, Republicans are going to have an extraordinary advantage that they haven’t had in 140 years,” Davis said.

Other analysts take a more cautious approach. Commenting on the congressional maps, Peace College political science professor David McLennan said, “The districts are not drawn in such a way that independents couldn’t move to the Democratic side and cause Democrats to win a number of those seats.”

Even districts that voted 55 percent for GOP presidential candidate John McCain in 2008 could be in play for Democrats in the right context, McLennan said.

At least in the near term, the rosy scenario for Republicans is contingent on courts OK’ing the maps in time for the 2012 election. During the last round of redistricting a decade ago, the plan got snarled in an extended legal battle that prompted state courts to impose a temporary set of legislative maps for the 2002 election. The same could happen next year.

“It’s the Republicans’ worst case scenario if they have to run in the current districts,” Davis said. “That would give Democrats a chance to recapture one of the houses.”

If history is any guide, the legislative redistricting plan will be appealed to the state Supreme Court. Although the court officially is nonpartisan, the Republican Party backs four of the seven justices, meaning a final ruling on a redistricting plan could be split along party lines.

As far as North Carolina’s new congressional districts, their fate rests in the hands of the federal government. If the Justice Department or the D.C. court deems the new boundaries harmful to minority voters, they can require legislators to redraw them.

Jane Pinsky, director of the N.C. Coalition for Lobbying and Government Reform, said the congressional maps don’t reflect the Tar Heel State’s political tendencies.

“We probably have five districts that are clearly Democratic, five that are clearly Republican, and three that are going to swing regularly,” she said. “The makeup of the delegation should reflect that.”

David N. Bass is an associate editor of Carolina Journal.