The lesser-known of two lawsuits aimed at taking down New York’s teacher tenure laws got a boost on Wednesday.

Longtime New York City education activist Mona Davids is teaming up with technology entrepreneur and Students Matter founder David Welch, who is fresh off of winning a legal battle against California’s tenure laws. Davids’ group, New York City Parents Union, filed its own version of Welch’s case, Vergara v. California, in New York last month.

Welch’s involvement in New York, first reported by the Daily News, will come with a major infusion of funding and legal expertise for Davids’ suit. It is also the second significant addition to the mounting fight against state teacher protection laws this week.

David Boies, a high-profile lawyer who fought to overturn state laws barring same-sex marriage, announced on Monday that he was joining the Partnership for Educational Justice, a group founded by former CNN anchor Campbell Brown that brought its own lawsuit against tenure last month.

Welch’s alignment with Davids’ lawsuit—and not Brown’s—reflects a key difference between the two lawsuits as originally filed. Davids’ original suit argued that tenure disproportionately saddles low-income and minority students with ineffective teachers, as was argued in the Vergara case. That complaint has been amended, and both lawsuits are arguing that teacher tenure leads to violations of a student’s constitutional right to a “sound, basic education.”

California’s constitution includes a clause guaranteeing equity in education. But that doesn’t exist in New York’s constitution—one reason lawyers for both groups have left that out of their main argument.

Davids’ lawsuit will also get new representation, Sam Pirozzolo, a Staten Island parent and plaintiff said. Randy Mastro, of the law firm Gibson Dunn, has signed on as attorney, taking the reins from Staten Island lawyer Jonathan Tribiano, who had limited experience with education law. (Tribiano will remain on the suit as co-counsel.)

Correction: An earlier version of this story incorrectly characterized the legal argument in the amended complaint, which you can read below: