Get ready for another showdown over privilege between the White House and Congress. Three House committees served subpoenas on Rudy Giuliani over Ukraine-Gate, setting up a fight over attorney-client privilege that will give federal courts another workout and even more headaches. Amazingly, Jerrold Nadler’s name doesn’t make the list:

Three House committees issued a subpoena Monday to President Trump’s personal lawyer Rudolph W. Giuliani, demanding he turn over all records pertaining to his contacts regarding Ukraine, the Biden family and related matters.

In a letter to Giuliani accompanying the subpoena, the chairmen of the three committees — Adam B. Schiff (D-Calif.) of the Intelligence Committee, Eliot L. Engel (D-N.Y.) of Foreign Affairs, and Elijah E. Cummings (D-Md.) of Oversight — cited “a growing public record” of information in accusing Giuliani of appearing “to have pressed the Ukrainian government to pursue two politically-motivated investigations.”

“The first is a prosecution of Ukrainians who provided evidence against Mr. Trump’s convicted campaign chairman, Paul Manafort. The second relates to former vice president Joseph R. Biden, Jr., who is challenging President Trump for the presidency in 2020,” the letter continued, demanding Giuliani turn over materials to their investigation by Oct. 15.

The letter also hints at a possible legal strategy for defeating a privilege claim:

The chairmen also said they are investigating “credible allegations” that Giuliani “acted as an agent of the president in a scheme to advance his personal political interests by abusing the power of the office of the president.”

If Giuliani himself was breaking the law, then privilege may not apply. Giuliani plans to make privilege an issue, however, remarking in an interview that the process is getting to look like a McCarthy-esque experience:

In an interview, Mr. Giuliani did not say whether he planned to comply with the subpoena. He denounced Democrats, accusing them of issuing an overly broad request. “We’re getting really close to, if we haven’t met, the standard of the McCarthy hearings where nobody seems to care about things like attorney-client privilege,” he said. …

Mr. Giuliani is mentioned frequently in the whistle-blower’s complaint and in recent weeks, he has admitted in interviews to trying to gather damaging information in Ukraine on Democrats, including Mr. Biden, that would help the president politically. He has also said the State Department was aware of some of his actions.

Mr. Giuliani has now been asked by House investigators for a range of communications and documents going back to January 2017. They include anything related to $391 million in American security aid that the Trump administration temporarily withheld from Ukraine and that Democrats have speculated may have been part of an effort to pressure the Ukrainian government.

How would the House committees get around an assertion of attorney-client privilege? It won’t be easy, but perhaps not impossible either. They would have to convince courts that Giuliani was either involved in criminal activity, which seems to be where the letter is leaning, or that he wasn’t working as an attorney at all but as Trump’s political “agent.” Both of those seem like tough sells in court. Going abroad and meeting with prosecutors and investigators, even as part of an oppo-research team, is not outside the ballpark for attorneys as part of their job in representing clients. Neither is it illegal, not unless Congress wants to get creative with the Logan Act, which a judge would likely laugh out of the courtroom.

There’s a third possibility, which is that the House could argue that Giuliani was acting as a de facto agent for the State Department. Congress does have some oversight on diplomatic affairs, and it does seem pretty clear that Giuliani was mucking about in foreign policy, at least to the extent of leveraging the US’ influence in Ukraine to reopen investigations into Burisma. The Los Angeles Times reported two days ago that Giuliani was pressuring prosecutor Yuri Lutsenko to dig up dirt on Hunter Biden, but Lutsenko insisted there was nothing to find:

Ukraine’s former top law enforcement official says he repeatedly rebuffed demands by President Trump’s personal lawyer to investigate Joe Biden and his son, insisting he had seen no evidence of wrongdoing that he could pursue.

In an interview, Yuri Lutsenko said while he was Ukraine’s prosecutor general he told Rudolph W. Giuliani that he would be happy to cooperate if the FBI or other U.S. authorities began their own investigation of the former vice president and his son Hunter but insisted they had not broken any Ukrainian laws to his knowledge.

Lutsenko, who was fired as prosecutor general last month, said he had urged Giuliani to launch a U.S. inquiry and go to court if he had any evidence but not to use Ukraine to conduct a political vendetta that could affect the U.S. election.

“I said, ‘Let’s put this through prosecutors, not through presidents,’ ” Lutsenko told The Times. “I told him I could not start an investigation just for the interests of an American official,” he said.

That certainly sounds as though Giuliani was doing a bit more than legal representation in Ukraine, but YMMV. The LAT suggests that Giuliani was also behind the decision to cashier US Ambassador to Ukraine Marie Yovanovitch earlier in the year when the Biden story heated up. That would give the House some backing for an argument that Giuliani was not acting as Trump’s personal attorney in Ukraine matters but as either Trump’s agent in an administrative capacity within the White House or the State Department. The lines certainly appear to have been blurred.

This runs into a few problems when it comes to impeachment, however. Giuliani may be a loose cannon, but he’s not going to throw Trump under the bus at any point, especially when none of this is actually illegal. It might be unethical and/or unwise at points, but it’s not illegal for Giuliani to hit up Lutsenko for dirt on the Bidens. The House can attempt to humiliate and bully Giuliani, but (a) he’s getting pretty used to that now, and (b) they really don’t have anything with which to threaten him except a contempt charge that the DoJ will never pursue. If Giuliani insists he did all this on his own, assuming he talks at all rather than assert privilege, it leaves impeachment without a key connection to even an assertable action by Trump on which to base it.

Also, we are dealing with executive authority at its zenith when it comes to foreign policy and diplomacy. That is exclusively the realm of the executive, with Congress only having oversight. Ambassadors serve at the pleasure of the president, who can replace them at any time for any reason. If Giuliani had something to do with that, it may reflect badly on Trump, but firing Yovanovitch is not an abuse of power; it’s an exercise of legitimate authority. So is calling another foreign leader and talking about corruption probes, even if the purpose of that is self-serving.

In the end, though, impeachment is a political act rather than a legal indictment. If a majority of the House believes that Trump used Giuliani to abuse his office for his personal or political gain, they don’t need to draw those lines to sustain an impeachment. They might need to do so to sustain their offices in the election that follows, and the Senate won’t remove a president without making those connections obvious, but it’s not a prerequisite to an impeachment itself. That’s where we seem to be heading, regardless of whether Giuliani’s covered by privilege or not, which might mean that these committees won’t bother with a long fight over these subpoenas in the end.