Democrats won a bittersweet victory in two key state Senate races in Tuesday’s special election.

Democrat Luis Sepulveda handily defeated Republican Patrick Delices and Reform Party candidate Pamela Stewart-Martinez in the 32nd District in the Bronx, and Democrat Shelley Mayer bested GOP candidate Julie Killian in a closely watched race in the 37th District in New York’s northern suburbs of Westchester.

But none of it matters. Democrats have a numerical majority of 32 to 31 in the state Senate, but they won’t regain power because of one breakaway Democratic senator who said Tuesday he would continue to caucus with the Republicans, at least through this legislative term, which ends mid-June.

The senator, Simcha Felder, made his decision Tuesday before the polls even closed, dampening Democrats’ victories.

“I believe it is my obligation to prevent an unprecedented and uncertain late-session political battle that will only hurt my constituents and New Yorkers,” Felder said in a statement, according to the New York Times. “Political gamesmanship must not be allowed to jeopardize the leadership, committee structure and staff of the New York State Senate and push this institution into turmoil.”

There was some speculation that if Democrats won the two open Senate seats, Felder would return to the fold, transforming the party’s numerical majority into an actual one. This could have given the Democrats control of the state government, with an overwhelming Democratic majority in the Assembly and a Democratic governor, Andrew Cuomo. (Nine seats in the state Assembly are also up for grabs, but the outcomes won’t significantly alter the lower chamber’s makeup.)

Instead, Felder’s decision to stay with the Republicans puts a truly blue New York frustratingly out of reach for progressives.

Meet Simcha Felder, the rogue Democrat who just spoiled the special elections

Felder was one of several rogue Democrats who for years played a weird game of caucusing with the GOP, leaving Democrats in the minority and stymieing opportunities to bring some legislation to the floor.

Some, like Felder, had distinct ideological differences. But the overwhelming reason for this strange marriage was power — being in the minority is not a fun place to be as a politician. It also came with some pretty good perks for the Democratic breakaways, including higher salaries.

But a recent deal with breakaway Democrats in the Independent Democratic Conference — brokered with help from Cuomo — brought most of the runaways back into the mainline fold. All of them, that is, except Felder.

Felder said he would wait until after the April 24 election to make his decision — but he preempted any election night celebrations by announcing his decision Tuesday afternoon.

A Democratic victory in New York’s 37th District can’t flip the state Senate

Two Senate vacancies were filled on Tuesday. One, in the 32nd District, covered a swath of the Bronx and leans heavily Democratic. Sepulveda, a Democratic Assembly member from the Bronx, was overwhelmingly favored.

That left the 37th District, a swing district that covers part of Westchester County. The race pit Democrat Mayer, a state Assembly member, against Republican Julie Killian, a member of a local city council who ran unsuccessfully for state Senate in 2016 against the Democratic incumbent.

If Killian had won, Republicans would have maintained the majority outright, and Felder wouldn’t have budged. But there were signs that Felder would reunite with the Democrats if Mayer won the race. As Doug Muzzio, a professor of political science at Baruch College, told Vox, Felder was the ultimate “wild card.”

Democrats would have eagerly welcome Felder back without question, and would have offered him some very favorable to concessions to secure that loyalty.

Felder also had something to gain by returning to the Democratic fold. The party is in a favorable position to take full control of the state Senate in November, when everyone is up for reelection. Any Democratic majority will be slim — but it might be just big enough that the party wouldn’t have needed Felder in the same way.

But Felder is a savvy politician, and effectively delivering the Republicans the majority probably won’t go unrewarded. It’s possible he’s also returning a big favor. As WXXI, Rochester’s public radio points out, Republicans helped ease restrictions on curriculum for Yeshiva religious schools — a key issue for Felder — in the recent state budget.

Still, at least one person with a lot of sway in Albany says it’s not over: Andrew Cuomo. A spokesperson for the governor said after Felder’s announcement: “The Governor’s position is clear: the Democrats must unify to take back the majority. This conversation will continue in the morning.”

It’s not clear if there’s a legitimate opening for the Democrats, or if Cuomo’s just trying to give himself cover in his primary race against Cynthia Nixon. The Independent Democratic Conference formed shortly after 2010, and the governor’s critics said the Republican-controlled state Senate gave him cover to govern down the middle. But a surprising challenge from Nixon in the gubernatorial primary suddenly made Democratic unity a top priority for Cuomo.

Felder’s decision won’t mean much in practical terms. The Albany legislative session is over in about two months. But the Democratic win on Tuesday put them in an even better position to retake the state Senate in November — with or without Felder. Felder does have a long-shot primary Democratic challenger. He’s not likely to lose, but Felder’s defection might motivate progressives across the state.