The Secretary argues both that the District Court had no jurisdiction to enter the TRO and that its ruling on the merits was erroneous. We express no opinion on the question whether HAVA is being properly implemented. Respondents, however, are not sufficiently likely to prevail on the question whether Congress has authorized the District Court to enforce Section 303 in an action brought by a private litigant to justify the issuance of a TRO. See Gonzaga Univ. v. Doe, 536 U. S. 273, 283 (2002); Alexander v. Sandoval, 532 U. S. 275, 286 (2001). We therefore grant the application for a stay and vacate the TRO.