Despite all the speculation about statutes that Donald Trump might have violated in his dealings with Ukraine, the two articles of impeachment unveiled yesterday are conspicuously lacking in specific criminal allegations. Instead, the articles allege that the president abused his powers by pressuring Ukraine to conduct investigations that would benefit him politically and that he improperly obstructed a congressional investigation of that abuse. To my mind, there is compelling evidence that he did both of those things.

Unfortunately, the record is not as complete as it could have been, as George Washington University law professor Jonathan Turley pointed out during his congressional testimony last week. The gaps in the case against Trump are big enough that his supporters can and will dismiss impeachment as a purely partisan exercise without losing any sleep about the broader issues at stake.

There were sound legal reasons for not accusing Trump of statutorily defined crimes. The most recently floated possibility, bribery, would require showing that Trump solicited "anything of value" (in this case, an investigation of his political rival) "in return for…being influenced in the performance of any official act" (in this case, the release of congressionally approved military aid to Ukraine that Trump had blocked). Even assuming the quid pro quo that circumstantial evidence and testimony by current and former administration officials strongly suggest, it is not clear that the "major investigation into the Bidens" Trump wanted would qualify as "anything of value." Turley argues that "the release of unspecified findings from an official investigation at some unspecified date are not a 'thing of value' under any reasonable definition of the statute."

There is a similar problem with defining the "favor" that Trump sought from Ukrainian President Volodymyr Zelenskiy as an illegal foreign campaign contribution. The relevant statute makes it a crime to solicit "a contribution or donation of money or other thing of value…in connection with a Federal, State, or local election" from a foreign national. The Federal Election Commission defines "thing of value" broadly: "'Anything of value' includes all 'in-kind contributions,' defined as 'the provision of any goods or services without charge or at a charge that is less than the usual and normal charge for such goods or services.'" But as Turley notes, Justice Department prosecutors who reviewed Trump's July 25 phone call with Zelenskiy "concluded that the call did not involve a request for a 'thing of value' under the federal law."

Furthermore, a felony charge under this statute requires that the contribution be worth at least $25,000, which would make it necessary to attach a dollar value to the speculative benefit that Trump's re-election campaign would receive from a Ukrainian investigation of the implausible allegation that Biden used his influence as vice president to protect his son. Finally, if dirt on Biden qualifies as a campaign contribution, so would compromising information about any candidate, which raises serious First Amendment issues.

Turley also considers the possibility of framing Trump's actions as extortion, which they certainly resemble as the term is commonly understood. "Extortion cases involve tangible property, not possible political advantage," he says in his summary of the case law. "The Biden investigation may have tangible political benefits, but it is not a form of property."

Turley, an expert on impeachment, emphasizes that "high crimes and misdemeanors" are not limited to statutory violations. "It is possible to establish a case for impeachment based on a non-criminal allegation of abuse of power," he says. "His [Trump's] call was anything but 'perfect' and his reference to the Bidens was highly inappropriate….The use of military aid for a quid pro quo to investigate one's political opponent, if proven, can be an impeachable offense." But Turley faults the House for rushing the process to meet a politically convenient goal of impeaching Trump by the end of this year.

"The House Intelligence Committee declared that it would not subpoena a host of witnesses who have direct knowledge of any quid pro quo," Turley says. "Instead, it [would] proceed on a record composed of a relatively small number of witnesses with largely second-hand knowledge." One can quibble with that characterization, since the record includes testimony about direct interactions between Trump and Gordon Sondland, the U.S. ambassador to the European Union, as well as between Sondland and Trump's personal lawyer, Rudy Giuliani, who Sondland understood was acting as the president's agent. But it's true that the case for a quid pro quo is based mainly on inferences and indirect evidence.

The decision not to subpoena directly relevant witnesses such as Giuliani, former National Security Adviser John Bolton, and acting White House Chief of Staff Mick Mulvaney was based on a desire to avoid time-consuming court battles over whether they could be compelled to testify. But as Turley notes, rulings involving Trump's financial records and the testimony of former White House Counsel Don McGahn suggest that Congress would have won those battles. Turley argues that litigation over documents sought by Congress and the testimony of Giuliani et al. could have been expedited, as similar litigation was in the Watergate investigation. Once Trump was confronted by court orders requiring his cooperation with the Ukraine investigation, Turley suggests, Congress would have been on firmer ground in accusing him of obstruction.

"One can oppose President Trump's policies or actions but still conclude that the current legal case for impeachment is not just woefully inadequate, but in some respects, dangerous, as the basis for the impeachment of an American president," Turley says. "This is an exceptionally narrow impeachment resting on the thinnest possible evidentiary record."

I have little doubt, based on the existing record, that Trump did in fact abuse his powers to serve his personal interests. But Turley is right that Congress could and should have done more to rebut Trump's defenses: that his desire for an investigation of the Bidens was based on a legitimate concern about official corruption in Ukraine and that, in any case, it was not connected to the delivery of military aid. While that first claim strikes me as wildly implausible, there is enough doubt about the quid pro quo to satisfy Republicans, even if they privately agree that Trump's request was inappropriate.

"The question for the House remains whether it is seeking simply to secure an impeachment or actually trying to build a case for removal," Turley says. "If it is the latter, this is not the schedule or the process needed to build a viable case. The House should not assume that the Republican control of the Senate makes any serious effort at impeachment impractical or naïve. All four impeachment inquiries have occurred during rabid political periods. However, politicians can on occasion rise to the moment and choose principle over politics."

As the record stands, it is not likely to persuade anyone who was otherwise inclined to support Trump, meaning we will get a party-line impeachment in the House, followed by a party-line acquittal in the Senate. What should have been a debate about the limits of tolerable presidential behavior has instead become another bitter partisan squabble signifying nothing but reflexive allegiance to arbitrarily defined tribes. While impeachment is inherently a political process, it cannot properly function as a check on presidential power when the public believes it is driven by nothing but politics.