When voters in Manhattan’s District 31, which includes parts of Harlem and Washington Heights, elected Marisol Alcantara to the New York Senate last year, they voted for a Democrat. They did so despite Ms. Alcantara’s expressed interest in joining a rogue group of Democratic state senators who collaborate with the Republicans.
Ms. Alcantara is a member of the Independent Democratic Conference, a group of breakaway Democratic state senators that caucuses with Senate Republicans. Her 2016 election helped give the minority Republicans the majority hold of the New York State Senate.
Under a 2012 agreement, Republicans and I.D.C. members share the leadership of the State Senate. And though Ms. Alcantara said she does not vote Republican, aligning with the I.D.C. gave her the support she needed for her campaign.
The I.D.C. directed its backers to financially support her candidacy. Once in Albany, she remained loyal to the I.D.C., crediting it with helping her become the only Latina in the state Senate.
Ms. Alcantara, a former labor union organizer who lives in Washington Heights, said she was also attracted to the I.D.C. by Diane Sevino, a State Senator representing District 23 who was also a former organizer.
“She came out of the labor movement, just like I did, and she offered to help and I said yes, why not,” Ms. Alcantara said.
Senate Democrats numerically hold the chamber’s majority by the smallest of margins — 32 to 31. But the I.D.C. has effectively rendered the Democratic Party the minority party. As well as wielding influence and power, I.D.C. also receives perks many mainline Senate Democrats do not, like committee leadership positions and bigger offices.
Ms. Alcantara, who was born in the Dominican Republic, said being a member has given her more power in Albany, something she feels is particularly important for a Latina. Most of the senators are white, and 49 of the 63 are men.
“It’s important to me as an immigrant, and as a woman of African descent and as Latina, to have a seat at the table and to speak to issues that are important to our community,” she said in an interview in her Washington Heights office.
But Ms. Alcantara’s departure from the mainline Democrats has provoked outrage in her community and in the United States Congress. A letter signed by the 18 New York Democrats in the House of Representatives, and sent to every State Senate Democrat in late May, calls for Ms. Alcantara and her colleagues to return to the fold.
Ms. Alcantara believes that despite appearances that she and the I.D.C. align ideologically with Republicans, the group backs many progressive positions, including abortion rights and single-payer health care.
But her detractors are unmoved. “I wonder if Senator Alcantara has trouble sleeping at night,” said Gus Christensen, a spokesman for No I.D.C. NY, a group created to support mainline Democrats in next year’s election. “Frankly, I hope she has trouble sleeping at night.”
The members of No I.D.C. NY feel Ms. Alcantara is a hypocrite: She supported Bernie Sanders, the Vermont independent, in the Democratic presidential primary race, is pro-immigrant rights and is a former union organizer. Mr. Christensen said that regardless of Ms. Alcantara’s views, the I.D.C.’s collaboration with Republicans means that legislation, such as single-payer health care, is unlikely to pass under a Republican-led State Senate.
Though protests have erupted outside her office, Ms. Alcantara says she is unlikely to budge. She said the opposition is provoked by people outside her district who are not in touch with the community.
“I am sure that none of those people who are out there protesting have managed to come to members of the Dominican community and asked them how they feel about me. Do they feel I’m a right-winger?” she said. “Some of the things they are saying are pretty stupid, like comparing me to Trump.”
On a recent Wednesday evening, a protest organized by No I.D.C. NY gathered outside Ms. Alcantara’s Washington Heights office at 5030 Broadway. The protesters denounced her collaboration with State Senate Republicans. It was one of eight protests held that day against the I.D.C., all in districts represented by the dissident Democrats.
Though Mr. Christensen led chants against Ms. Alcantara, he said that should she decide to return to the mainline Democratic conference, she would be received with open arms. But the consequences of remaining in the I.D.C. could hurt her re-election bid in 2018, he believes. “If she stays in the I.D.C., she’s the one who’s most likely to lose.”
But to some residents of District 31, Ms. Alcantara’s allegiances aren’t as important as her ethnic background. Outside her office, a group of counter protesters waved Dominican flags and posters that said “Immigrants deserve representation” and “We support Marisol, the only Latina in Senate.”
“She works for the community and everything she does is to defend our community,” said Juana Ciriaco, 56, a Washington Heights resident who was waving a poster supporting Ms. Alcantara. “Whatever she thinks is good for the community, she does it.”
Ms. Ciriaco said she had never heard of the I.D.C. “The community is not going to stop supporting her,” Ms. Ciriaco said. “We trust her.”
As she spoke, the two sides challenged each other. Anti-I.D.C. protesters — most of them white — promised to unseat her next year. In response, supporters — many of them Spanish speakers — told the protesters to “check their privilege.”
Francesca Castellanos, 48, said she doesn’t believe Ms. Alcantara represents the Dominican population, but thinks the discussion around Ms. Alcantara’s I.D.C. allegiance shouldn’t be about race.
Ms. Castellanos, a Dominican interpreter who lives in Washington Heights, said that by being a member of the I.D.C., Ms. Alcantara is neglecting her community’s needs. The senator’s job, Ms. Castellanos said, is to represent the entire district, not just one nationality or race.
“In this country, when you go vote there’s not a flag,” Ms. Castellanos said. “Laws and policies cannot benefit one nationality from the other.”
But Ms. Alcantara disagrees.
“I think it’s important for even young people to have people that look like them, and government should be representative of the people that it serves,” she said. “As much as New Yorkers talk about how progressive they are, unfortunately when it comes to politics and power, it’s not representative of the city’s population.”