From the opinion:

In sum, while the First Amendment interests of WFA and its donors at stake in this case are substantial, WFA has failed to make a showing that it would suffer irreparable harm if its motion for a preliminary injunction is denied. Contrary to WFA’s contention, it need not refrain from spending more than $250 on independent expenditures in order to protect the identities of its donors. And while the timing and wording of its solicitations of contributions may trigger a duty to disclose donors who respond to such solicitations, the record is not sufficiently developed to permit the kind of relief WFA has requested.