WASHINGTON >> Democrats pushed today for a special prosecutor to examine the Trump administration’s potential ties to Russia, using a confirmation hearing to urge the No. 2 pick at the Justice Department to consider handing over any such investigation to an independent overseer.

“We need steel spines, not weak knees when it comes to political independence in the Department of Justice,” said Sen. Dianne Feinstein of California, the Senate Judiciary Committee’s top Democrat.

The remarks came during a hearing for Rod Rosenstein, a longtime federal prosecutor tapped for deputy attorney general, which instead became a referendum on Russian meddling in the presidential election.

As deputy, Rosenstein would assume oversight of a federal investigation into Russian influence following the recusal last week of Attorney General Jeff Sessions, who said he would step aside from any probes into the Trump campaign after revelations of unreported contacts with the Russian ambassador last year.

Though repeatedly pressed by Democrats, Rosenstein would not commit to appointing a special prosecutor and said he was unaware of a basis to do so at the moment.

Rosenstein responded in lawyerly fashion to hours of questioning, saying he had no direct knowledge of any Russia-related investigation and had not read the intelligence community’s formal assessment that Russia interfered during the campaign on behalf of President Donald Trump. That review, from the country’s intelligence agencies, concluded in January that Russian intelligence agencies were behind the hack of Democratic National Committee networks and had worked to harm Hillary Clinton’s chances of election.

He promised to handle that investigation like any other if evidence of criminal wrongdoing emerged.

“I don’t know the details of what if any investigation is ongoing, but I can certainly assure you, if it’s America against Russia or America against any other country I think everyone in this room knows which side I’m on,” Rosenstein said.

That commitment was not enough for some Democrats on the Senate Judiciary Committee.

Sen. Richard Blumenthal said he could not support Rosenstein’s nomination — despite his apolitical reputation and service as a U.S. attorney under presidential administrations of both parties — unless Rosenstein could commit to recusing himself and appointing what some have taken to calling a special prosecutor — though special counsel is technically the correct title.

“I say so with some sadness and regret because of my respect for you, but this issue of principle is so profoundly important. Only you — only you — have the power to appoint a special prosecutor,” said Blumenthal, D-Conn.

He added: “We are in an extraordinary time, careening toward a constitutional crisis with the intelligence agencies in complete agreement that the Russians launched a massive attack on our democracy.”

The committee chairman, Sen. Charles Grassley, said such calls were premature and that the appointment of a special counsel was not the best way to ensure transparency.

“There is no mandatory public report or other finding at the end of the investigation if no charges are filed. The investigations can just disappear into a black hole without the public ever understanding what the facts were,” said Grassley, R-Iowa.

Rosenstein passed up opportunities to criticize Trump for his unsubstantiated assertions on Twitter that President Barack Obama had ordered his phones tapped during the campaign, though Rosenstein did say that any such action would have to be done through a court order and with ample probable cause.

Asked about any of his own contacts with Russian officials, Rosenstein said he had not knowingly had any such interactions, though he did acknowledge that as U.S. attorney, he has had meetings with visiting lawyers from abroad.

“Over the course of my career from time to time, I have spoken to groups of visiting lawyers and judges from foreign countries,” Rosenstein said. “It’s certainly possible there may have been Russian officials there. But I don’t recall any such meetings, no.”

The deputy attorney general is responsible for day-to-day operations and oversight of the Justice Department’s law enforcement component agencies such as the FBI.

Rosenstein has served as U.S. attorney for Maryland since 2005, having been appointed by President George W. Bush and then serving for the duration of the Obama administration.

Rachel Brand, another former Justice Department attorney, also faced a confirmation hearing today for the job of associate attorney general, the department’s No. 3 position.