RALEIGH — Federal court rulings made clear long ago that a state constitutional ban on dividing counties cannot be enforced, state attorneys argued before the North Carolina Supreme Court on Thursday.

"The General Assembly has treated those clauses as invalid and unenforceable since 1982," said Eddie Speas, chief deputy attorney general.

Speas and the state are defending a lawsuit brought by Republican lawmakers who claim Democratic legislative leaders ignored the whole-county provision when they redrew state House and Senate districts last year.

The House plan divides 70 of North Carolina's 100 counties to form 112 districts. The Senate map divides 51 counties to establish 46 districts.

Before a packed courtroom of about 125 people, many of them top political leaders, the seven justices heard oral arguments in the case. Many of the Democratic and Republican leaders sat side-by-side, some of them joking with each other prior to the hearing.

The hearing was the first ever from the state Supreme Court shown live on television, broadcast on a local cable news channel.

Speas, the lead lawyer handling the case for the state, told the justices that both the U.S. Voting Rights Act and federal protections for proportional representation essentially forced counties to be divided, superseding the state constitution.

Republican lawyers, though, argued that Section 5 of the Voting Rights Act applies only in 40 North Carolina counties, meaning the legislators have no right to ignore the state constitution in the state's other 60 counties.

"There is no other state in the union that hasn't adopted this theory, that hasn't rationalized and harmonized their constitution provisions with whatever the federal law is," said attorney Tom Farr.

However, some of the justices were clearly troubled by what that "harmonization" would look like.

Republicans have submitted proposed legislative district maps which don't divide counties but create large multimember districts. In Mecklenburg County, some voters would be put into a district that includes 10 House members and five Senate members.

Another five-member Senate district - with a population as large as a congressional district - stretches from Caswell through Rockingham, Randolph and portions of Forsyth and Guilford counties.

"If you have a large group of eight or nine people running (from one district), how does that best serve democracy?" Justice Mark Martin asked.

Justice Bob Orr asked whether lawmakers could keep county lines intact but create single-member districts within them.

Farr, though, said the state constitution makes no provision for dividing counties in that way.

Famed civil rights attorney Julius Chambers, arguing on behalf of the NAACP, said surrounding single-member minority districts with huge multimember and largely white districts would violate principals of proportional representation.

"You are telling black voters, I am going to give you one person to vote for. You are telling white voters, I am going to give you eight to vote for," Chambers said.

The court did not reach a decision in the case Thursday, and it was not clear when it would rule. The justices have already agreed to delay the May 7 primary pending a ruling in the case.

If justices agree with Republican plaintiffs, they could throw out the new districts, ordering lawmakers to redraw them before elections can be held. Or the justices could allow the 2002 elections to proceed with the current districts and order lawmakers to redraw them next year.

The state could also seek another appeal to federal court if a ruling goes against it.