House Democrats want Robert Mueller’s testimony to be something that it’s not. They want President Trump gone, and they think Mueller, the former special counsel, will help them sink his presidency.

During his congressional testimony on Wednesday, one line of questioning continued to appear: Should President Trump be charged with obstruction of justice? And would Mueller have suggested indictment if Trump were not president?

Democrats must have known Mueller would lead them to a dead end. He made it clear in his report that he did not charge the president because of a long-standing policy instituted by the Office of Legal Counsel that states, “The indictment or criminal prosecution of a sitting President would unconstitutionally undermine the capacity of the executive branch to perform its constitutional assigned function.”

Mueller restated this precedent, put in place during the Nixon impeachment saga in 1973 and reaffirmed in 2000 after the Clinton scandal: “We, at the outset, determined that, when it came to the president’s culpability, we needed to go forward only after taking into account the OLC opinion that indicated that a sitting president cannot be indicted.”

When pressed, Mueller clarified that Trump could, in fact, be charged after he leaves the White House. Democrats grabbed onto this statement as some kind of lifeline, but Mueller didn’t say anything we didn’t already know. This rule has been in place for decades; it’s not a new concept.

The irony is that Democrats don’t need Mueller to get rid of Trump. They can do it themselves: Democrats control the House and can begin impeachment proceedings at any point. But still, they rely on Mueller to give them some sort of validation.

They won’t find it: Mueller made it clear in his report that he would not give a definitive answer on whether Trump obstructed justice — even if his conclusions suggest he personally believes Trump broke the law, as my colleague Tiana Lowe wrote. Mueller is constitutionally and legally correct: It’s not up to Robert Mueller whether Trump is guilty of a crime. It’s up to Congress. The legislative branch is responsible for keeping the president accountable, and it is up to the House and Senate to determine whether there is enough evidence to begin the impeachment process.

Democrats certainly seem to think Trump is guilty of obstruction. Several House members said as much during their questioning, and they’ve been affirmed by a handful of the party’s 2020 presidential candidates. If Democrats truly believe Trump broke the law, then it is their constitutional obligation to hold him accountable. But they won’t act because they know impeachment is a lost cause. It doesn’t have popular support and would be struck down the moment it entered the Senate. So, Democrats look to Mueller for validation: Perhaps if Mueller says explicitly that Trump obstructed justice, they’ll have a winning case against the president. And if they don’t, they’ll have a scapegoat to blame.

Mueller isn’t willing to play their game. Mueller did his job and made his conclusions. If Democrats disagree, they should step up and do the same.