WASHINGTON — The 23rd Congressional District already sprawls across all or part of 11 counties. It covers more than 14,739 square miles.
But somewhere, it needs about 53,000 additional people to survive as a district next year.
The 23rd, represented by Rep. William L. Owens, D-Plattsburgh, is hardly alone. Every district from Plattsburgh to Jamestown is well short of the 717,707 people needed to make a district after adjustments for the 2010 census.
All 435 House districts must have the same population, with little deviation allowed. Because New York's population grew more slowly than other states, it will lose two seats in the next Congress, the U.S. Census Bureau reported.
The 23rd District has 664,245 people, the Census Bureau found. To pick up 53,462 people, it must expand into other districts south and west — which also must take in territory to expand to 717,707.
The way to fix that domino effect is to eliminate a district in Western New York, where population fell sharply, say political scientists who follow redistricting.
All district boundaries will change, but the biggest adjustments may well come in the areas with the sharpest declines, they say.
Most of the chatter about new congressional lines focuses on Western New York and possibly somewhere downstate, not in the north country. So the likelihood of the region being divided among neighboring districts may be less because the population stayed more or less intact compared with 2000.
By that view, Reps. Louise M. Slaughter, D-Fairport, and Brian Higgins, D-Buffalo, may be in trouble. Their districts have the farthest to go to meet 717,707. But politically, erasing two districts in the same region is a tough sell, so Long Island might be an alternative, said Bruce E. Altschuler, a political science professor at SUNY Oswego.
"My feeling is that the two parties will cut a deal," Mr. Altschuler said Friday.
That might mean Mrs. Slaughter's or Mr. Higgins's district, and then perhaps the Long Island district represented by Rep. Peter King, whose controversial hearings on Islam could make him more of a target politically.
The state Legislature and governor are in charge of redistricting in New York, although the GOP-led state Senate wields the most influence.
Mrs. Slaughter could be forced into a primary with Mr. Higgins. Or she could retire, though she has not publicly indicated she is considering that.
On the other hand, census numbers do not support eliminating a district in Long Island, said Andrew A. Beveridge, a professor at Queens College who specializes in redistricting.
The two districts in Long Island are not as far off from the target of 717,707 as other areas, Mr. Beveridge said.
If the New York Public Interest Research Group expects two seats to disappear downstate, Mr. Beveridge said, "I don't know what they've been drinking."
On the other hand, he said, downstate areas did not gain nearly as much population as some experts predicted, Mr. Beveridge said.
Indeed, NYPIRG said it expects both seats to be lost downstate because of proportionately strong population growth in the Hudson Valley, while other downstate areas underperformed.
By NYPIRG's estimate, downstate areas should have 16.7 seats and upstate areas 10.3, based strictly on population numbers. Downstate now has 19.
NYPIRG has urged the Legislature to adopt a redistricting policy that relies more on the census and less on political deals and gerrymandering.
"Unless reforms are put in place, the process will again be driven by decisions to protect incumbents and to sustain the legislative majorities," NYPIRG said in a news release.