In 2008, Felder challenged incumbent State Senator
Kevin Parker in a Democratic primary in Senate District 21. Parker won the primary with less than 50% of the vote. Felder was elected to the
New York State Senate in
District 17 in November 2012. The district had been reconfigured as a "Super Jewish" district; reportedly, the Republican-controlled chamber drew the district specifically with Felder in mind. Even though incumbent David Storobin had won the seat in a special election, the GOP offered little support to him, and Felder handily defeated him. Felder also stated his willingness to return to the Senate Democratic Conference if doing so would benefit his district. Brooklyn Democratic Party Chairman
Frank Seddio called Felder's defection a "disgrace and a complete betrayal of his constituents". As a State Senator, Felder was the only Democrat to vote against $15-per-hour minimum wage legislation. He cast deciding votes against an immigration bill called the
New York Dream Act, stated that ending
stop-and-frisk was a mistake, opposed plastic bag fees, and supported Iran divestment and
anti-BDS laws. Felder opposes abortion. On the final day of the 2013 legislative session, Felder voted against a hostile amendment that would have attached a pro-choice bill to an unrelated piece of legislation; the measure failed by one vote. Felder was re-elected to the Senate without opposition in 2014 and 2016. In the latter election, he ran on the Democratic, Republican, and
Conservative lines. In April 2018, other lawmakers accused Felder of "essentially holding the $168 billion budget hostage until the state agreed not to interfere with the curriculum at the private Jewish schools known as yeshivas". After an April 2018 agreement returned the
Independent Democratic Conference (a breakaway faction of Democrats) to the mainline Democratic conference, Felder became the swing vote in the State Senate; this placed a spotlight on his continued affiliation with Senate Republicans. On April 24, 2018, Felder announced that he intended to continue caucusing with Senate Republicans during the remaining weeks of the 2018 legislative session; Felder made this statement despite the possibility that two special elections being held that day could give the Democratic Party a numerical majority in the State Senate, and despite Governor
Andrew Cuomo's public support for Democratic control of the Senate. On April 25, Cuomo sent Felder an open letter to pressure him to rejoin the Senate Democratic Conference. Felder continued to caucus with the Republicans. In the 2018 Democratic primary in September 2018, Felder defeated Blake Morris, a lawyer. Felder won re-election on November 6, 2018. The 2018 elections saw the Democrats win control of the State Senate for only the second time since
World War II. Felder sought to rejoin the Senate Democratic Conference. However, on December 31, 2018, the Senate Democratic Conference announced that Felder would not be allowed to rejoin its ranks. Even without Felder, the Democrats had 39 Senate seats, seven more than the 32 needed for a majority. On January 9, 2019, the
Daily News reported that Felder had decided against caucusing with the Republicans, and was looking forward to rejoining the Senate Democrats "'at the appropriate time'". Felder was accepted into the Democratic caucus on July 1, 2019, after having voted with the Democrats on multiple major pieces of legislation. In 2022, following redistricting, Felder - who represented New York's 17th Senate District - sought re-election in New York's 22nd Senate district. Felder won re-election in the 22nd Senate District in November 2022. Felder's final day in the legislature was April 9, 2025. He stepped down from his Senate seat after being elected to the New York City Council. His farewell speech marked only the third time he had ever spoken on the Senate floor. ==New York City Council (2025–present)==