(Andrew Harrer/Bloomberg News)

Another House Republican announced his retirement Tuesday, putting a closely divided district at risk for the GOP.

Rep. Frank A. LoBiondo (R-N.J.), a 12-term congressman, said he would not seek reelection next year, citing in a statement the expected loss of key committee posts and an increasingly bitter political environment.

“People before politics has always been my philosophy and my motivation,” he said in a statement. “Regrettably, our nation is now consumed by increasing political polarization; there is no longer middle ground to honestly debate issues and put forward solutions.”

New Jersey’s 2nd Congressional District includes much of the southern third of the state, including Atlantic City and shore towns stretching from Barnegat Light to Cape May. While LoBiondo has won comfortably since he was first elected, in 1994, the district is almost evenly divided between Republicans and Democrats and instantly becomes one of the most likely seats to switch parties in the 2018 midterms.

The nonpartisan Cook Political Report rates the district as having a one-point GOP lean. Its voters picked Donald Trump by five points over Hillary Clinton in last year’s presidential race, but Barack Obama twice carried the district. Numerous Democrats hold state and local offices in the district and could be formidable candidates.

There are also signs that the national Republican agenda is unpopular in the district: LoBiondo voted against the GOP health-care bill earlier this year that would have undone much of the Affordable Care Act. And he has withheld support for the pending GOP tax bill, citing its disproportionate impact on his constituents through the loss of key deductions.

“LoBiondo has consistently opposed his own party’s harmful policies, and it’s clear he was no longer willing to be associated with establishment Republicans in Washington,” said Democratic Congressional Campaign Committee spokesman Evan Lukaske, who added that “Democrats are confident that a strong candidate will step up” to run for the seat.

Rep. Steve Stivers (R-Ohio), the chairman of the National Republican Congressional Committee, said that “while Frank’s leadership will be sorely missed, I am fully confident a strong Republican nominee will hold the seat and continue delivering results for the 2nd District.”

In his statement, LoBiondo said he is in good health and that his decision was “not electoral.” Key nonpartisan House forecasters predicted LoBiondo would have been likely to keep his seat had he chosen to run again.

Instead, like Reps. Jeb Hensarling (R-Tex.) and Lamar Smith (R-Tex.), who also recently announced their retirements, LoBiondo cited the consequences of internal GOP rules that will force him from key committee posts.

“As I am term-limited as Chairman of the House Aviation Subcommittee and in my position on the House Permanent Select Committee on Intelligence, now is appropriate time to leave,” he said before adding a more pointed comment on the contemporary House: “Those of us who came to Congress to change Washington for the better through good governance are now the outliers. In legislating, we previously fought against allowing the perfect to become the enemy of the good. Today a vocal and obstinate minority within both parties has hijacked good legislation in pursuit of no legislation.”

LoBiondo is one of only six House Republicans currently in Congress who took office as part of the landmark “Republican Revolution” class of 1994. The others are Reps. Steve Chabot (Ohio), Rodney Frelinghuysen (N.J.), Walter B. Jones (N.C.), Mark Sanford (S.C.) and Mac Thornberry (Tex.).