From the Morning Memo:

In the six years since Sen. Simcha Felder has been in the state Senate, he has never been a formal member of his own party’s conference.

But that’s changing, as the Brooklyn lawmaker, once a key member of the Republican conference, is officially joining the Senate Democrats, giving them 40 members in the 63-seat chamber.

“Following a successful and historic legislative session, Senator Simcha Felder will be the newest member of the Senate Democratic Majority,” said Senate Majority Leader Andrea Stewart-Cousins in a statement.

She pointed to Felder’s support for measures, including a law that will allow undocumented immigrants to apply for driver’s licenses, the package of sweeping rent control law changes and gun control provisions.

“At the start of this past session, I made clear that we wanted to begin with the 39 Senators who were committed to being members of our conference, but that we were open to growing if other Senators displayed a desire to advance our Democratic agenda,” Stewart-Cousins said.

“This year, Senator Felder joined our Senate Democratic Majority in support of many crucial issues, including the strongest tenant protections in history, the new Green Light law, voting reforms and legislation to prevent gun violence. Accordingly, we will move forward with 40 diverse and united members joined by a shared commitment to continue delivering progressive results for our state.”

Felder, a registered Democrat, had an alliance with Senate Republicans that proved fruitful, including the chairmanship of a subcommittee on issues facing New York City education.

Through it all and as pressured built for him to join with Democrats, Felder had insisted he would do what was best for his constituents.

Felder had been a man without a conference for the first six months of the year after Republicans lost control of the majority, sitting on the far out ring of lawmakers in the state Senate.

A year ago, he was in a powerful position last year, when the Independent Democratic Conference dissolved and rejoined the mainline conference of Democrats, leaving control of the Senate on a knife’s edge.

Felder, as the decisive lawmaker giving Republicans the majority last year, remained with the Senate GOP despite entreaties from Democrats and an unsuccessful effort to primary him.

Democrats won control later that year in November in a landslide.

Now, with 40 members, Democrats are two seats shy of a 42-vote supermajority.

“I look forward to working together with my Democratic colleagues on behalf of my constituents and all New Yorkers,” Felder said.