President Trump said on Wednesday that he was delaying his nomination of Jay Clayton as director of national intelligence as he again tried to pressure Congress to pass a strict voter identification law that does not have enough support to advance.
Mr. Trump nominated Mr. Clayton, the U.S. attorney in Manhattan, last week after senators from both parties condemned his earlier decision to appoint Bill Pulte, a top housing official, to the post.
But just hours before Mr. Clayton was scheduled to have a confirmation hearing before the Senate Intelligence Committee, Mr. Trump said in a social media post that he would delay the proceedings. That would leave Mr. Pulte, who has no known national security experience, as the acting director of national intelligence.
A decision to cancel the hearing would be typically be made by the committee. Representatives for the panel’s Republican chairman, Senator Tom Cotton of Arkansas, and its top Democrat, Senator Mark Warner of Virginia, did not immediately respond to requests for comment.
Senate leaders had been hoping that Mr. Clayton could be quickly confirmed, seeking to bring his nomination to the floor as soon as Thursday. That would clear the way for a bipartisan deal to reauthorize one of the government’s most powerful surveillance tools, Section 702 of the Foreign Intelligence Surveillance Act.
That program — a warrantless surveillance law that lets the government collect the private communication of foreigners — lapsed last week, after Democrats who had been working with Republicans on an agreement to renew the law said they would not vote to do so unless Mr. Trump withdrew Mr. Pulte’s nomination.
In his post on Wednesday, Mr. Trump claimed that Democrats had violated an agreement to reauthorize the surveillance program after he nominated Mr. Clayton.
But he then added another condition to extending Section 702, saying that he would not approve doing so unless the reauthorization was attached to elections legislation that would impose national restrictions on voter identification and registration.
Mr. Trump has declared that bill, the SAVE America Act, his top legislative priority and the key to Republicans winning the midterm elections.
“To add a slight bit of intrigue but, for the Good of the Nation, and the People of our Country, I will not approve FISA without THE SAVE AMERICA ACT going along with it,” Mr. Trump said in his social media post.
But Republicans do not have the votes to overcome Democratic opposition to the voting bill, and there is not sufficient support among G.O.P. senators to undermine the filibuster.
“We are bound by arithmetic in the United States Senate,” said Senator John Thune, Republican of South Dakota and the majority leader, in a Fox News interview on Tuesday. “The votes currently aren’t there.”
Mr. Trump also said that he would not remove Mr. Clayton from his role as U.S. attorney before his replacement, James M. McDonald, one of the president’s personal lawyers, was approved by Congress.
Under a longstanding Senate practice known as the “blue slip,” home-state senators can block some federal prosecutorial nominees. For Mr. McDonald to advance, the two Democratic senators from New York — Chuck Schumer, the minority leader, and Kirsten Gillibrand — would need to approve his nomination.
Mr. Trump, who has long been frustrated that Senate traditions have stymied his agenda, attacked the blue slip in his social media post and urged Republicans to abandon it.
