Almost immediately after the news broke of Ms. Katz’s breakthrough, people began speculating about more nefarious explanations.
In particular, Ms. Cabán’s supporters have accused the Queens County Democratic Party, whose leaders supported Ms. Katz, of engineering the disqualification of so many affidavit ballots. They pointed out that the commissioners of the Board of Elections are selected by the county party leaders, before being approved by the City Council.
Shaun King, a prominent progressive activist, wrote on Twitter that the Queens County Democratic machine had tried to “steal” the election for Ms. Katz. State senators Alessandra Biaggi and Julia Salazar, who won their seats last year by challenging incumbent Democrats from the left, also blamed Ms. Katz or the county commissioner for Ms. Cabán falling behind.