Adam Schiff owes the public some answers.

The House Intelligence Committee chairman should explain why and under what authority he obtained and then publicized phone records that included calls involving the president's personal attorney Rudy Giuliani, ranking Intelligence Committee Republican Devin Nunes, journalist John Solomon, and others. It is far from clear when, or even whether, House subpoena powers extend so far without a court-ordered search warrant.

The California Democrat has used the records to hint at attempts by the Trump team and by Nunes, Schiff’s bitter rival, to coordinate a pressure campaign against Ukraine for Trump’s personal benefit. Solomon, meanwhile, was the conduit for much of the reporting, some of it from dubious sources, that Trump’s defenders have cited as the reason Trump wanted certain Ukrainian actions investigated.

The exact scope of congressional subpoena power is a legal gray area, frequently fought over in the courts without clear resolution. In Schiff’s favor, Congress arguably deserves more latitude amid impeachment proceedings. And as Giuliani and his associate Lev Parnas are both reportedly under investigation by divisions of the Justice Department, it is possible, if one stretches the imagination, that Schiff was somehow just piggybacking on those investigations to secure their phone logs.

But Schiff is on dangerous ground by publicizing phone calls by fellow members of Congress and journalists. Perhaps Schiff merely stumbled across Nunes's and Solomon's calls because they involved Giuliani or Parnas. But it sets a dangerous precedent that journalists, protected with good reason by the First Amendment, or members of Congress, protected with good reason by the Constitution's speech or debate clause, should be thus exposed by a committee chairman just to score what appears to be a few extra political points.

Nunes's phone calls probably do not merit speech or debate protection. But they might, and it is not a frivolous question. If a member of Congress takes an action connected to oversight — for example, speaking on the phone with someone tasked by the president to do something in Ukraine — the courts have ruled that the pertinence of this action to the speech or debate clause “does not hinge on the formality of the investigation” but on "whether information is acquired in connection with or in aid of an activity that qualifies as ‘legislative’ in nature.” Maybe it's a crazy idea, but there probably ought to be a presumption against leaking a political rival's phone activity in this manner. In fact, Schiff's behavior in this regard resembles that for which he now hopes to impeach the president.

There are other concerns here, as well. In the context of executive law enforcement, Fourth Amendment protections against unreasonable searches and seizures generally require permission from judges or magistrates. In other words, the “checks and balances” of the system require two of the three branches, not just one, to agree that the search is necessary and lawful. If Congress, meaning Schiff, acted without judicial imprimatur, then the legitimacy of his phone-records search is certainly questionable.

Meanwhile, if he did subpoena Solomon’s calls — again, this is not entirely clear — that would also raise serious issues related to press freedoms, in addition to the Fourth Amendment concerns. Schiff needs to clear up why Solomon’s calls were included in his dragnet. Their release appears to be an act of petty vengeance against someone whose reporting followed the wrong narrative.

Schiff owes the public absolute transparency here about his methods, and he must provide legal justifications that clear a fairly high bar. Yes, his exercise of power may conceivably have been legitimate, but count us unconvinced. Absent a full and convincing explanation, the phone-records search was presumptively invalid.