The 2002 round of redistricting was a rare moment of harmony in New Jersey politics, with all 13 members of the congressional delegation coming together and agreeing on a compromise map that they all felt had their best political interests in mind.

That was then; this is now.

With the state losing one seat in the decennial re-sorting of congressional districts, there is plenty of consternation about just which area will get the ax.

With no member of the delegation likely to retire and only one statewide office – that of Sen. Bob Menendez (D) – up in 2012, it’s quite possible that all 13 members will be seeking reelection and two incumbents will be running against each other.

As for who those two incumbents will be, it’s really anybody’s guess.

New Jersey is one of six states that has a redistricting commission. Six appointed Democrats and six appointed Republicans – two each from the parties’ chairmen, Assembly leaders and Senate leaders – work together. If a majority of the 12 can’t come to an agreement, a neutral 13th person plays the role of mediator/tie-breaker.

It’s a system that could lead to some middle ground in the process. The question now is where that middle ground will be found.

The state’s delegation is currently comprised of seven Democrats and six Republicans – about right for a state that leans Democratic.

But when you strip one seat, the math gets harder. Does the commission draw seven Democratic districts and five Republican districts (putting two Republicans together) or six apiece (putting two Democrats together)? Or do they draw six Democratic districts, five Republican districts and one swing district (putting a Republican incumbent and a Democratic incumbent together)?

Even once it’s established what the breakdown should be, there are any number of ways for the commission to go to accomplish its preferred split. And that means a lot of scared incumbents right about now.

“I expect that you will see a more contentious process in congressional redistricting in New Jersey than you just saw for legislative redistricting,” said New Jersey Democratic attorney and redistricting expert Donald Scarinci, who recently published a book on the topic.

About the only people who are safe in this process are Democratic Reps. Donald Payne and Albio Sires in the New York City metro area and Democratic Rep. Rob Andrews in the Philadelphia metro area. Payne and Sires represent majority-minority districts (African-American and Hispanic, respectively) that will in all likelihood remain largely as-is, while Andrews represents a relatively concentrated and strongly Democratic district in South Jersey.

On the GOP side, the most likely member to remain unscathed is Rep. Frank LoBiondo, whose large South Jersey would be tough to combine with another.

As far as the state’s other nine members, nobody is feeling too safe right now.

It would take far too much time to go through all the possible scenarios, so here are the most popular theories, and why they do (and don’t) make sense.

* Rep. Bill Pascrell (D) vs. Rep. Steve Rothman (D)

Combining these two incumbents is, at a glance, the most logical solution. That’s because their districts lost more people than anyone but Payne (who is untouchable), and because they live just a couple miles from each other in Bergen County.

(Follow along on the congressional map here.)

But putting Pascrell’s Paterson-based 8th district and Rothman’s Hackensack-based 9th district together wouldn’t necessarily be so easy. For one, it’s hard to see Democrats accepting any map where there are six districts apiece for each party, given their historic dominance in the state. They would likely need some concessions elsewhere on the map – i.e. making GOP Reps. Leonard Lance or Jon Runyan more vulnerable. But under that scenario, you’ve got three upset incumbents rather than just two. Not optimal.

“That’s a fairly remote possibility,” Scarinci said.

* Two North Jersey Republicans face off

Since North Jersey is now under-populated, it seems logical that the eliminated district would come from there. And if you’re looking to eliminate a Republican district, you’ve got to choose some combination of the three Republicans – Rep. Scott Garrett in the northern 5th, Lance in the swing 7th and Rep. Rodney Frelinghuysen in the Morris County-based 11th.

Neither Lance nor Frelinghuysen is going to want to face Garrett in a primary under any circumstance given how much more conservative Garrett’s record is. The Frelinghuysen name is an institution in New Jersey GOP politics, while Lance is in just his second term, so the most logical solution would be Garrett versus Lance.

But again, would Republicans, after GOP Gov. Chris Christie’s big 2009 win, accept losing a seat without getting anything in return? Maybe they’s negotiate a better shot at taking out Democratic Reps. Rush Holt and/or Frank Pallone in the central part of the state. But again, that would create headaches for more than two incumbents.

* Rep. Frank Pallone (D) vs. somebody

Ask anyone who Christie would most like to draw out of a seat, and the answer is unanimous – Pallone. Pallone was the Democratic pitbull in the 2009 governor’s race and has clearly earned the ire of a governor who is not afraid of a political fight. Christie expended plenty of political energy in state legislative redistricting; does he do it again in congressional redistricting?

If he does, hey may push for Republicans to dismantle Pallone’s district. The problem is that Pallone is from the Shore, just north of Asbury Park, while everyone he could be matched up with would be from the near the Delaware River – the western border of the state. The theory is that his district could be split between some combination of the more urban districts to the north, Lance, Holt and Rep. Chris Smith (R). Most likely, Pallone would then live in Smith’s central Jersey district. But he could also be paired with Holt.

(Fun fact: Pallone was drawn into a district with another Democrat 20 years ago, after a Democratic plan tried to put he and Smith into the same district.)

The problem with that scenario is that it’s very tough to give Pallone a fair shake in a matchup with Smith, who is the dean of the delegation. And a matchup with Holt would get rid of a Democratic seat – a non-starter for Democrats.

Pallone is also tied for the longest-serving Democrat in the delegation, so he would appear an unlikely target.

* Something involving Rep. Jon Runyan (R)

As the delegation’s newest member, Runyan would seem to be the most obvious target. Democrats would like to win his district back after losing it in 2010 (former Rep. John Adler was a potential rematch candidate before his untimely death earlier this month), while certain powerful forces in the GOP would like to turn Runyan’s district into more of an Ocean County district.

It’s not clear what an agreeable solution would be that would involve Runyan, though, because if you dismantle his district, the North Jersey districts would have to collapse significantly southward, and lots of members would have very different districts than they have now.

What’s more, the only Democrat you can combine Runyan with (without a huge gerrymander) is Andrews, and that would likely be a political death sentence for Runyan. Drawing an Ocean County district, meanwhile, would probably put Runyan and Smith together in a neighboring district, failing to eliminate a district. Yet again, you would have more upset incumbents than you need to have.

Much like Pallone and the Republicans, eliminating Runyan is great for Democrats in theory, but tough in practice.

Which brings us to the middle-ground option…

* Rep. Rush Holt (D) vs. Rep. Leonard Lance (R)

Holt’s Trenton-based 12th district and Lance’s 7th share a big border in Hunterdon and Somerset counties, and it wouldn’t be difficult to draw them both into a swing district while keeping everybody else safe and happy. Pallone’s 6th district, which went overwhelmingly for Christie, could pick up more of Democratic Middlesex County, while Smith’s central 4th district could take some Monmouth County Republicans from Holt. Meanwhile, the more Republican portions of Lance’s district could go to Frelinghuysen and Garrett up north.

Holt doesn’t play the political game as much as many of his colleagues, he’s the least senior Democrat outside of Sires (who is untouchable), and his district is the most accessible to be paired with a Republican colleague. So he may be draw the short straw here.

It makes sense for Lance, too, given that he ran in the 12th district primary in 1996 and represented part of Holt’s district in the state Senate before joining Congress. Lance also has the second-least seniority, behind Runyan, and happens to be right in the middle of where changes seem likeliest to occur.

“He’s in a really bad spot geographically,” said a Republican familiar with the state’s redistricting process.

But, as is often the case in New Jersey politics, predicting just what will happen is difficult at best and foolhardy at worst.

If you talk to 10 New Jersey politicos about congressional redistricting this year, they will give you 10 different predictions about just what will happen.

And all of them could very well be wrong.