RALEIGH, N.C. — It wasn't surprising when a panel of federal judges struck down North Carolina's congressional map, saying Republican state legislators went too far using political data to preserve GOP-held seats. But their suggested timetable to fix the problem was startling.

The judges this week raised the possibility of redrawing the districts by mid-September so they could be used in November elections, or at least before the next session of Congress is seated in January. Late congressional elections could bring huge attention to these races if the party that controls the U.S. House hasn't been settled.

Republican state legislative leaders said Tuesday a quick redraw of 13 congressional districts would lead to "unmitigated chaos and irreparable voter confusion." Primaries were already held in May using the current maps, which had been approved for 2016 elections.

But the state Democratic Party says voters "should not have to suffer through yet another election" with unconstitutional districts. Some previous boundaries approved in 2011 were struck down more than four years later as racial gerrymanders.

Monday's decision on two partisan gerrymandering lawsuits largely mirrored the panel's January ruling. The U.S. Supreme Court had directed the judges to revisit the matter based on a Wisconsin case.

WHAT HAPPENS NEXT?

The three-judge panel asked the parties in the lawsuits — election advocacy groups, Democrats, Republican mapmakers and the state elections board — to say by Friday whether the 2016 maps should be used again. They also want to know whether the GOP-dominated General Assembly should get another crack at redrawing the maps, potentially by mid-September.

Writing for the panel, U.S. Circuit Judge Jim Wynn said they would normally allow the state to wait for districts to be redrawn in 2020.

In fact, when a similar panel that included Wynn struck down nearly 30 legislative districts in August 2016, the judges wrote that November's elections could continue under the old maps because it was too late to change them then.

But Wynn wrote there are "unusual circumstances" that make elections under new lines possible this fall. They include a showdown between Democratic Gov. Roy Cooper and Republican lawmakers over proposed constitutional amendments that have delayed the printing of ballots.

The panel also plans to hire an outside expert to draw an alternative plan as a backup plan. They've asked the parties for some suggestions for a "special master" by Wednesday.

APPEAL TO SUPREME COURT?

Wynn suggested primaries for redrawn seats could be held in November, with a general election before Congress convenes. Or there could be only a general election, presumably with any number of candidates affiliated with multiple parties running for each seat.

Republican legislative leaders disagree with the ruling and say they would ask the Supreme Court to block any lower-court decision requiring a new map be drawn so elections could be held under them now.

While justices have been wary in the past of altering the rules so close to an election, the retirement of Justice Anthony Kennedy means there are now eight people on the court. A 4-4 split would mean the lower court ruling would stand, and elections under new districts would be required. The justices could still hear the bulk of the case later.

CAN IT BE DONE?

Election officials would face severe challenges holding congressional elections in November under a new map. Some say it's impossible.

Wynn mentioned Sept. 17 as a possible deadline for lawmakers to submit redrawn districts. That's just five days before federal law requires absentee ballots to be sent to military and overseas voters.

The plaintiffs would be allowed to file objections to that plan, Wynn wrote. Usually there's a new candidate filing period, while election officials would have to code new district information for nearly 7 million registered voters and prepare new ballots.

Gerry Cohen, a former longtime legislative staff attorney and election matters expert, said he can't see how elections could be held on Nov. 6. There are two workable options, Cohen tweeted — either wait until 2020 elections or hold elections in early January through a process in which party activists choose the nominees.

WHAT'S AT STAKE

With control of the U.S. House on the line, the two major parties already were gearing up for competitive races in North Carolina and raising millions of dollars.

Democrats already appear to be targeting the 9th and 13th Districts seats held by the GOP. And President Donald Trump planned to attend a fundraising luncheon Friday in Charlotte for 13th Rep. Ted Budd and 9th GOP candidate Mark Harris.

While the judicial panel found 12 of the 13 congressional districts violated the equal protection provision of the U.S. Constitution, all 13 would have to be altered. A rewrite would likely open more opportunities for Democrats to pick up more seats. Republicans currently hold 10 of the state delegation's 13 seats.