The first round of hearings is over. More than a dozen closed-door depositions are out in the open. The impeachment inquiry is headed into its next phase.

After weeks of laying out their evidence, Democrats will now decide which potential charges to level against against President Trump. Unless additional public testimony is scheduled, that means the center of gravity in the impeachment process will soon shift to the House Judiciary Committee, which is holding its first hearing on impeachment on Wednesday. That committee is expected to draft articles of impeachment based on a forthcoming report from the House Intelligence Committee.

At various points, Democrats have said that they already have the “smoking gun” evidence needed to convince the public that Trump’s conduct was serious enough to warrant his removal from office. And throughout the impeachment process, Democrats have laid out a detailed timeline they say implicates Trump and his allies in a scheme to pressure Ukraine to pursue investigations of the president’s political rival. But while the House seems likely to vote on impeachment, the impact of the case against Trump may ultimately depend on what the American public — not the House Democrats — regards as the “smoking guns.” As we await the release of the Democrats’ report and the next round of hearings, it’s a good moment to take stock of the “smoking guns” they have — and don’t have.

There is, at present, no single piece of evidence that conclusively links Trump to the Ukraine scandal like the tape transcript of President Nixon ordering the Watergate cover-up. That particular piece of evidence was such a decisive “smoking gun” that its release forced Nixon’s resignation within a matter of days. Democrats’ case against Trump, on the other hand, doesn’t have that one key piece of evidence directly linking Trump to a quid pro quo. So a question moving forward is whether Democrats have enough of a “smoking gun” to persuade voters that Trump committed impeachable offenses — or if the missing evidence will turn out to be a lifeline for Trump.

In broad strokes, Democrats laid out three questions at the beginning of the public phase of the inquiry, which they said would serve as the foundation for their investigation (and perhaps also the articles of impeachment). Those questions are:

Did Trump request an investigation that would personally benefit his political interests? Did Trump and his allies pressure Ukraine into committing to an investigation, including threatening to withhold a White House meeting or military aid? Did the White House then try to suppress or conceal information about Trump’s actions with regard to Ukraine?

Democrats’ evidence for the first question — that he asked a foreign leader for an investigation of his political rival — is particularly strong. They don’t just have a single smoking gun regarding whether Trump or the people close to him asked the Ukrainian president and other high-level officials to open an investigation into the Bidens — they have a whole smoldering arsenal.

Particularly key is the summary of the July 25 call between Trump and Ukrainian president Volodymyr Zelensky, which was actually released before Democrats even began interviewing witnesses. (The White House released the summary a month after a whistleblower filed a complaint about the call.) In the now-infamous conversation, Trump asked Zelensky to “do us a favor” and open investigations into 2016 election interference and the Bidens. While Trump has denied that he did anything wrong on the call, that summary is proof that Trump mentioned investigations to Zelensky, and makes it pretty hard to argue that Trump didn’t want Ukraine to open them.

That’s important because over the course of the public testimony, the Democrats have also tried to establish that this wasn’t just a one-off request. According to Gordon Sondland, the American ambassador to the European Union and an integral figure in pushing for the investigations, he and others were just following the president’s orders, something which he testified that Trump had made clear on several different occasions. That testimony was underscored by an account from a second witness, diplomat David Holmes, who said he overheard a call between Sondland and Trump on July 26, where Trump reportedly asked Sondland about whether Zelensky was going to commit to the investigations. Sondland disputed a few of Holmes’s details in his testimony, like whether he mentioned the name “Biden.” But he largely agreed with the substance of what Holmes said, adding to the Democrats’ evidence that Trump himself was asking about investigations.

Whether Democrats have a smoking gun for their third question — if there was an effort to cover up or suppress information about Trump’s actions on Ukraine — is more debatable. They don’t, for example, have much evidence from the hearings of an internal effort to cover up the July 25 call. Several witnesses were questioned about why the July 25 call record was moved onto a secure server, or why a few words and phrases seemed to be missing from the call summary. But none of them were willing to say they saw a concerted effort to conceal information.

An obstruction charge is still on the table, though, as Democrats have indicated they could instead draft a narrower article of impeachment around obstruction or contempt of Congress, focusing on the White House’s blanket refusal to cooperate with the inquiry. Democrats like Rep. Adam Schiff, the chairman of the House Intelligence Committee, have already said that this is an impeachable offense. Whether the public will agree remains to be seen, since this has been the Trump administration’s attitude toward all congressional investigations since Democrats took control of the House.

But of course, the Democrats are still missing perhaps the most essential piece of the puzzle — a smoking gun for their second question of whether Trump ordered that military aid and/or a White House meeting be conditioned on the investigations.

To be sure, Democrats do have a wide array of evidence strongly suggesting that the people involved in pushing for the investigations — including the Ukrainians — understood that a White House meeting and nearly $400 million in military aid hung in the balance. Multiple witnesses testified over the course of the public hearings that it was clear to them that there was a quid pro quo. But as Republicans pointed out repeatedly over the course of the hearings, none of these witnesses ever talked to Trump directly. Even Sondland, the one witness who did communicate with Trump directly about the investigations, said he only “presumed” there was a connection and had never heard Trump say it.

There are other witnesses who could help fill in the blanks. Acting White House chief of staff Mick Mulvaney, who witnesses say delivered Trump’s order to freeze the aid, seems like he’s in a position to shed light on at least some of this mystery. And Rudy Giuliani, the president’s personal lawyer, would also presumably be able to offer crucial input about his involvement in the pressure campaign, too — since witness after witness described him as the person tasked with carrying out Trump’s orders. Of course, the rub is neither seems likely to comply with the Democrats’ subpoena to testify, so Democrats have said they’ll press ahead with the impeachment process rather than try to force Mulvaney and others to testify through what would almost certainly be a lengthy court battle. Democrats did score a win in court last week in case involving another recalcitrant witness, former White House counsel Don McGahn, when a judge ruled that White House officials can’t ignore congressional subpoenas — but that ruling is under appeal, and it’s not clear how it would affect other impeachment witnesses.

It’s possible, too, that this particular “smoking gun” — that is, direct evidence that Trump ordered a quid pro quo — might not exist. It could be that Trump truly didn’t make the connection or as Trump’s former personal lawyer, Michael Cohen, testified earlier this year, it could because Trump frequently speaks in “code,” rather than giving direct orders. That doesn’t mean that the connection between the investigations, the aid, and the White House meeting wasn’t apparent to everyone involved. But it does potentially deprive Democrats of a smoking gun as dramatic and decisive as the tape that ended Nixon’s presidency. Over the next few weeks, we’ll see just how much of a barrier that turns out to be.