“He thinks that the ‘speech or debate’ clause is a core protection for Article I, for the legislature,” said one of the two people familiar with Pence’s thinking, who spoke on condition of anonymity to discuss his legal strategy. “He feels it really goes to the heart of some separation of powers issues. He feels duty-bound to maintain that protection, even if it means litigating it.”

Pence’s planned argument comes on the heels of an FBI search of two of his homes after his attorney voluntarily reported classified material in his home last month — drawing him into a thicket of document-handling drama that’s also ensnared Trump and President Joe Biden. While Pence aides say he’s taking this position to defend a separation of powers principle, it will allow him to avoid being seen as cooperating with a probe that is politically damaging to Trump, who remains the leading figure in the Republican Party.

Pence is preparing to launch a presidential campaign against his onetime boss. Aides expect the former vice president to address the subpoena — and his plans to respond it — during a visit to Iowa on Wednesday.

But regardless of its political consequences, the argument from Pence’s camp means Smith could be in for a legal mess.

That’s because the legal question of whether the vice president draws the same “speech-or-debate” protections as members of Congress remains largely unsettled, and constitutional scholars say Pence raising the issue will almost certainly force a court to weigh in. That could take months.

“It is admittedly a constitutionally murky area with no clear outcome,” said Mark Rozell, a George Mason University political scientist who specializes in executive privilege. “Since there is a legislative function involved in the vice president presiding over the Senate, a court very well could decide that it must address the scope of the speech or debate privilege and whether it would apply in this case.”

Although vice presidents aren’t technically senators, they are charged with breaking tie votes in the upper chamber. And every four years, on Jan. 6, they lead the electoral vote count that facilitates the transfer of power from one administration to the next. Trump’s months-long crusade to pressure his vice president to derail Biden’s win — which is central to Smith’s investigation — focused entirely on Pence’s duties as Senate president, which legal scholars say lends credence to Pence’s case.

“I do think there’s a plausible [speech or debate] argument here,” echoed Josh Chafetz, a Georgetown University constitutional law professor. “And I’d be surprised if Pence doesn’t eventually make it. After all, a lot of the action here took place in terms of arguments about how he should rule from the chair.”

The clash arrives at a sensitive moment in Smith’s probe, which appears to be nearing its conclusion. Typically, prosecutors wait to subpoena top officials until right before making charging decisions. In addition to the demand for Pence’s testimony, a parade of high-level Trump administration witnesses has marched into the sealed grand jury rooms of Washington’s federal courthouse in recent weeks.

And it presents a new wrinkle for Pence as he makes moves typical of a White House hopeful, including his trip to Iowa this week. After confronting the 2020 election head-on late last year with a book and op-ed, he’s largely avoided a topic that risks courting confrontation with his former boss and possible future presidential opponent.

Most commentary since Smith subpoenaed Pence has focused on whether Trump might prevent Pence from testifying by asserting executive privilege — an unwritten constitutional protection that lets presidents maintain the confidentiality of high-level conversations (a Trump attorney told CNN Sunday that Trump intends to assert executive privilege over Pence’s testimony).

But seeking congressional immunity would further help Pence avoid a Trump collision and might prove more effective — a point legal scholars say is being overlooked. That’s because unlike executive privilege, which has limits that can be overcome in criminal proceedings, “speech or debate” clause protections have remained mostly impenetrable in investigations relating to the official duties of lawmakers, their aides or other congressional officials.

DOJ has, notably, argued in civil litigation that the “speech or debate” clause protects the vice president when working on Senate business. The department explicitly asserted in 2021 that Pence was shielded by the “speech or debate” clause in a civil lawsuit related to his role presiding over Congress’ Jan. 6 session.

The Senate, too, has long maintained that vice presidential involvement in its business “would fall within the legislative sphere and be protected by the speech or debate Clause.”

Courts have never explicitly ruled on that front, but have hinted over the years that vice presidents should enjoy some level of constitutional privilege stemming from their unique role in two branches of government.

A ‘first time’ argument

Roy Brownell, former counsel to Senate Minority Leader Mitch McConnell and author of a prominent paper on vice presidential privilege, said that if Pence ultimately asserts “speech or debate” protections, it will be “the first time it’s ever been clearly expressed that the vice president is claiming his own constitutional privilege.”

Even when Dick Cheney sought to expand the powers of the vice presidency to a historically unprecedented degree — triggering numerous court battles — he never formally invoked the protection, Brownell noted.

Brownell also emphasized that court rulings have found that “speech or debate” protection applies to congressional officials performing “fact-finding” related to their jobs. Pence, he said, could characterize his pre-Jan. 6 conversations with Trump and others as research into how he might rule on matters related to the Electoral College.

It’s still unresolved whether the Jan. 6 session of Congress legally counts as “legislative” business, however. In addition, even if courts deem Pence’s role a legislative one, judges would still have to decide whether the “speech or debate” clause protects him from having to testify about his conversations with Trump world about the bid to upend the election.

“It’s a fair question,” said Stan Brand, who was general counsel of the House of Representatives under former Speaker Tip O’Neill. “Procedurally, it creates another layer of potential judicial adjudication and that will certainly complicate the effort to enforce the subpoena.”

Some experts pointed to the recent 11th Circuit Court of Appeals decision that paved the way for Sen. Lindsey Graham (R-S.C.) to testify to local investigators in Georgia — who are also probing Trump’s effort to subvert the election. Graham initially protested, contending the “speech or debate” protection should shield him from testifying at all.

But the circuit ruled that Graham could be compelled to testify so long as investigators steered their questions away from anything involving his legislative responsibilities. The Supreme Court declined to step in.

Pence may ultimately land in the same place, but it’s unclear which aspects of his involvement in the Jan. 6 session of Congress would fall outside of his official duties. High-level Trump administration witnesses, as they warned the then-president not to pressure Pence over how he counted electoral votes, made clear they viewed him as occupying a uniquely legislative role on Jan. 6.

“The Vice President is acting as the President of the Senate,” former assistant attorney general Steven Engel recalled telling colleagues in testimony to the Jan. 6 select committee. “It is not the role of the Department of Justice to provide legislative officials with legal advice on the scope of their duties.”

The counterpoint

Not all legal scholars agree that vice presidents enjoy congressional privileges, however. Former White House counsel Neil Eggleston said the text of the “speech or debate” clause doesn’t apply to anyone but lawmakers.

“The literal language is that this applies to ‘senators and representatives,’” said Eggleston, who advised former President Barack Obama from 2014 to 2017. “I think, by the language, this does not apply and the argument is completely frivolous.”

Still, predicting exactly how courts would handle the argument is difficult. The Supreme Court has repeatedly upheld the executive privilege wielded by presidents, despite the Constitution making no reference to the concept.

Meanwhile, the GOP House is fighting a grand jury proceeding of its own against Rep. Scott Perry (R-Pa.), who is citing the same constitutional protections to shield his communications from Smith and his team.

Perry, a key ally in Trump’s bid to seize a second term, has contended the “speech or debate” clause should bar prosecutors from accessing his phone — which the FBI seized last year — but a federal judge ruled against him in December. An appeals court secretly put that ruling on hold last month and scheduled oral arguments on the matter for Feb. 23. The House filed a lengthy brief Monday to defend Perry’s argument.