Orthodox Jewish elected officials and community leaders gathered to endorse in a new, heavily Orthodox State Senate district Tuesday.

“I sing your praises, sometimes I get in trouble for doing that but I will continue to do it forever,” Democratic Assemblyman Dov Hikind told Republican State Senator Dean Skelos on his post-Shabbos radio show late last Saturday night. “I just want to personally thank you for being so amazingly responsive to all of New York State, but to the Jewish community in particular. You are really just a superstar.”

Mr. Skelos, the leader of the New York State Senate and one of the “three men in a room” that control decision-making in Albany, received this high praise for adding yeshiva tuition tax credits into the state budget and his recent work to fund bus service to those same private religious schools. Mr. Hikind is a longtime assemblyman and power broker in the Jewish neighborhoods of southern Brooklyn and, despite being a Democratic Party official, has been more than willing to endorse Republicans.

At the end of last year, Mr. Skelos traveled to the Masbia soup kitchen in the Flatbush section of Brooklyn where, after donning a velvet yarmulke, he chopped carrots, peeled potatoes and ladled kosher soup to the needy. He proceeded to tell a story about smuggling Jewish artifacts into the Soviet Union and joked that his own Greek Orthodox beliefs gave him insight into Orthodox Judaism, letting Yiddish words like tzitzis and shul roll off his tongue all the while. Cameras rolled and mobile phones snapped photos for the Jewish media to consume later, of course.

Mr. Skelos is hardly the first powerful politician to make the pilgrimage to Brooklyn’s kosher soup kitchens, but he is the most notable Republican to do so in recent years, demonstrating a new reality that a swath of heavily Democratic Brooklyn and Queens is ready to vote for candidates who belong to the same party as Mitt Romney and Rick Santorum. Indeed, Mr. Skelos and his Republican colleagues drew a new State Senate district in southern Brooklyn this year and packed it with as many Orthodox Jewish voters as possible. In past redistricting cycles, the district lines suggested Republicans sought to dilute the Orthodox vote.

In addition to Mr. Skelos, a healthy string of ambitious Democratic citywide and local elected officials have made the soup-ladling trek, which says nothing of their efforts to pay tribute to other prominent Jewish social service organizations but also speaks volumes about the community’s growing political significance.

“The Orthodox community is growing as a percentage of the population—and a percentage of the vote—every single day,” Mr. Hikind told The Observer last week. “If there’s one group that’s not leaving the city, that’s staying here, that’s buying homes, it’s the Orthodox community.”

This demographic shift, augmented by Jewish immigrants from the former Soviet Union, has transformed much of the Jewish landscape of the city, according to Michael Tobman, a political consultant who has helped advise campaigns and organizations in Brooklyn’s Orthodox Jewish neighborhoods.

“I would say the trend is not just about Brooklyn politics,” he said. “The trend is internal to the Jewish community … which is to say older, middle-aged and more secular Jewish voters like my parents—two retired teachers and civil servants in Brooklyn—just don’t have the numbers anymore. It’s a tsunami of Haredi, Orthodox and Russian-speaking Jews.”

While some of this population surge is due to Hasidim, the traditionally garbed community whose cultural practices often lead to large families of 10 or more children (and whose neighborhoods voted more heavily for John McCain in 2008 than the State of Utah), the larger Orthodox Jewish population is experiencing explosive growth in New York City as well.

“The Hasidim have large families, but so do people in the Flatbush-Midwood areas,” Mr. Hikind said. “My daughter has five kids! The idea of having large families goes way beyond the Hasidic community.”

Although this has been an ongoing phenomenon, the political implications of this trend have suddenly become noticeable in two special elections taking place over the past year. After Congressman Anthony Weiner infamously tweeted an unfortunate part of his anatomy to the world at large, culminating in his resignation, Democrats were initially confident that their dominating registration advantage in the district would allow their nominee, Assemblyman David Weprin, to sleep through an easy election. After all, the consensus went, the same district that elected liberal firebrands like Anthony Weiner, Chuck Schumer and Geraldine Ferraro couldn’t possibly elect a Republican, especially some unknown like Bob Turner, a retired Breezy Point businessman and presumed sacrificial lamb. They were in for a rude awakening.

Even though Mr. Turner, a genial 70-year-old grandfather, comes from Irish Catholic stock and Mr. Weprin is a practicing Orthodox Jew, Mr. Turner successfully made the election about “sending a message” to President Obama about his administration’s policies on Israel. He was further helped by Mr. Weprin’s affirmative vote on gay marriage, a move that caused significant backlash in the community. For example, the prominent local newspaper Hamodia declared that Mr. Weprin sold “his very soul” with the vote in an editorial entitled “David Weprin, Who Are You?” Mr. Turner also shrewdly focused his campaign’s spending on Jewish and Russian media with audiences geographically concentrated in the district, allowing him to leverage his shoestring campaign into a five-point upset victory and a new job in Washington.

Mr. Turner has since declared his candidacy for the U.S. Senate seat held by Kirsten Gillibrand. Both he and his supporters point to his support among Jewish voters when giving his electoral pitch to his fellow Republicans.

The second recent special election demonstrating the increasing influence of the Orthodox community took place in the exact same corner of southeastern Brooklyn as Mr. Turner’s current congressional district. The vacancy opened up last December after Democratic State Senator Carl Kruger found himself in his own scandal, which was slightly more serious than Mr. Weiner’s, as Mr. Kruger ended up pleading guilty to federal corruption charges.

Again, the neophyte Republican candidate in the race, attorney David Storobin this time around, was able to surprise the political consensus that assumed the Democratic candidate, Councilman Lew Fidler, would easily claim victory (The New York Times reported during the election that political analysts saw Mr. Fidler “as the overwhelming favorite in the district”). Although the results of the election are still in doubt—the most recent count on Monday had Mr. Storobin up by only three votes with an ongoing fraud lawsuit still to be resolved, likely followed by an automatic hand recount of all 20,000 ballots—the results were still impressive for the Republican and a symbolic sign of Democratic weakness among electorally important constituencies.

Mr. Fidler even had an extensive track record of funding significant Jewish social service organizations, and he worked as a volunteer attorney for the Hasidic leadership in Crown Heights in the aftermath of the 1991 riots. Yet he still lost badly in the neighborhoods where observant Jews are most concentrated.

“We can really make a difference, we can really make a difference whether it be gay marriage or Israel with Obama. The Turner-Weprin race was really amazing,” said Mr. Hikind, who crossed party lines to endorse Mr. Turner in that election. “The Storobin race was the same thing.”

“This has always been a swing community, but there hasn’t been a good opportunity for them to vote for Republicans before,” one prominent Jewish leader, who requested anonymity so he could speak candidly, explained to The Observer. “A lot of it has to do with social issues like gay marriage that are coming to the forefront. It was always sort of a back-burner issue but those issues are becoming starker.”

He also pointed out that New York City Democrats tend to be far more liberal than the Democratic Party as a whole, an attribute that could further separate them from moderate and conservative Orthodox voters.

“If you look at the Orthodox community, especially the ultra-Orthodox community, they don’t do TV, they don’t do sports. Politics is a big deal,” he said. “Politics is a massive interest in the community. People follow elected officials.”

And even though the community’s voters might side strongly with the Republican candidate in the 2013 mayoral race, they are mostly registered as Democrats and candidates seeking to win the Democratic primary are extensively courting the community.

“The community is very aware that the winner of the Democratic primary is likely to be the next mayor because of the current lack of a credible Republican candidate,” Councilman David Greenfield said when asked about the race. “As a result, I believe that you will see very high Orthodox Jewish turnout in the 2013 Democratic primary. The community also recognizes that if it’s a tight race, the seven or eight percentage points that the Orthodox Jewish vote makes up in a primary could definitely make the difference.”

The candidates involved all seem to recognize this reality and are doing much more to engage these voters than sending out platitudinal statements commemorating Jewish holidays. As the candidates competing for the nomination are nearly identical on social issues, some have been working to separate themselves in other ways.

For example, Public Advocate Bill de Blasio started up his own Iran boycott website and has held press conferences on the issue. He also took a firm stance against the Park Slope Food Co-op possibly boycotting Israeli products, calling it “wrongheaded and an affront to American values and interests.”

Other likely mayoral candidates, such as Manhattan Borough President Scott Stringer, Comptroller John Liu, former Comptroller Bill Thompson and Council Speaker Christine Quinn, may be relying on more direct appeals through surrogates and appearances in Jewish neighborhoods, although their exact campaign strategies have yet to unfold. However, Ms. Quinn, an open lesbian whose political brand is intertwined with the LGBT movement, could have trouble winning over these socially conservative voters despite her more moderate ideological profile. Mr. Stringer is the lone top-tier Jewish candidate in the race, and his path to victory could rely on running up solid numbers in these Brooklyn precincts.

And, unsurprisingly, all five of the top candidates in the race have ladled kosher soup at Masbia, four of them in the past year. A sixth candidate, newspaper publisher Tom Allon, recently traveled to Israel and wrote an op-ed declaring, “New York needs a mayor like me who thinks like an Israeli: tough and always ready to defend his people.”

“You ask a very interesting question,” Mr. Hikind mused when asked which candidate would have the edge in the 2013 race. “If there’s no issue of someone who’s a conservative candidate, who fits our agenda better, it becomes a question as to who’s going to be there on issues important to the community. Who’s going to be there for us?”