New Jersey Democrats are moving to change the process by which the state's legislative districts are drawn, advancing a bill that would put the high-stakes political issue to voters through a constitutional amendment.

Their plan, opposed vociferously by Republicans, would change the composition of the Apportionment Commission and use data from all statewide general elections - for governor, U.S. Senate, and president - held in the previous decade to draw the political map.

The wonky, math-intensive matter of redistricting helps shape the balance of power in Trenton and in statehouses across the country. Democrats in Trenton have won an advantage in each of the last two maps, drawn in 2011 and 2001. They control both houses of the Legislature.

Congressional redistricting is a separate process that wouldn't be affected by the amendment.

The latest effort, which has unfolded in Trenton over the last two weeks, comes nearly five years before the next map will be drawn. The state constitution requires the Apportionment Commission to redraw the districts every decade to account for changes in the Census.

Voters elect one senator and two Assembly members to represent each of the state's 40 districts.

Democrats say they want to put the issue on the ballot in 2016 because the presidential election will result in high voter turnout, and thus greater voter participation.

To get the question on next year's ballot, the Legislature would need to pass the bill with majority votes both this session, which ends in mid-January, and next, or with one three-fifths majority vote.

Republicans have not minced words in their criticism.

"This is not our finest moment. It's a terrible moment for democracy," State Sen. Kevin O'Toole (R., Passaic) said during a Senate Judiciary Committee hearing Monday, when Democrats advanced the measure on an 8-5 vote along party lines. O'Toole, instead, offered an amendment to impose term limits, which Democrats shot down.

"Historically anti-American," offered Sen. Gerry Cardinale (R., Bergen).

"Doubling down on stupid," said Assemblywoman Holly Schepisi (R., Bergen), referring to the second legislative hearing she had attended on the matter in less than a week.

The principal target of their frustration: a provision in the bill that would require "at least" 25 percent of all districts, or 10 of the 40 total, to be competitive.

The legislation defines a competitive district as one that is more favorable to either party by no more than five percentage points of the "average district," which would be calculated by using voting results in the statewide elections.

If the districts were to be redrawn today, the "average district" would lean 54 percent Democratic and 46 percent Republican, said Assembly Majority Leader Louis D. Greenwald (D., Camden), a sponsor of the bill.

The commission would also be required to ensure that each party has an equal number of "favorable" districts, relative to the average.

Republicans object that the 25 percent requirement would constitutionally enshrine an anticompetitive map, thereby deterring voters from heading to the polls and undermining the democratic process.

'Unregulated whims'

Greenwald argued that his plan would actually increase competitiveness because only a handful of districts have been truly contested in recent election cycles.

In an interview, he said it was "not geographically possible" to draft a map in which every district was competitive, because there are pockets of the population that are overwhelmingly Republican or Democratic.

The amendment also would change the composition of the Apportionment Commission. Currently, each party chair appoints five members, and the chief justice of the state Supreme Court appoints a tiebreaker in the event of an impasse.

Under the amendment, each party chair would appoint three members, and the four leaders of the Legislature - the Assembly speaker, Senate president, and minority leaders in the two houses - would each appoint one. The chief justice would appoint a tiebreaker at the outset of the reapportionment process.

"In our opinion, the map should be in control of the voters," Greenwald said, "not the unregulated whims of a tiebreaker."

In another change, state legislators would be prohibited from serving on the commission, which supporters said would combat parochial interests.

Supreme Court case

Democrats are moving ahead with the bill even as the U.S. Supreme Court is reviewing a case challenging the "one person, one vote" principle that undergirds federal law governing the political process.

The plaintiffs, from Texas, want each district to have the same number of eligible voters - not the same total population, which includes children, noncitizens, and others who can't vote.

Opponents of the New Jersey legislation note that if the Supreme Court rules in favor of the plaintiffs next year, lawmakers would have to change the state amendment, voiding any vote held this session.

A Supreme Court decision is expected in June.

Still others suggest that the plan, which is being rushed through the lame-duck session, is a plot by Democrats to ensure they maintain an outsize majority in perpetuity.

"Politics is about winning; nobody knows that better than the other party," said Assemblyman Michael Patrick Carroll (R., Morris). "And they've been very good at it. If you're the Democrats, and you've had two beautiful cycles which have delivered magnificent results, why change?"

856-779-3846 @AndrewSeidman