If Donald Trump instructed his attorney Michael Cohen to lie under oath to Congress about planning a Trump real estate development in Moscow in the midst of the presidential campaign, he is almost certainly a felon. As attorney general nominee William Barr testified earlier this week in response to a question from Senate Judiciary Committee Chairman Lindsey Graham, suborning perjury in the midst of an investigation is the sine qua non of the crime of obstruction of justice. The remaining question is whether Republicans will join Democrats in calling for the president’s removal from office.

If Graham is remotely principled, he will lead his party in calling for the president’s removal, just as he advocated for the impeachment of President Bill Clinton under far less egregious circumstances 20 years ago.

He should be joined by former special prosecutor Ken Starr, who in 1998 presented a report to Congress purporting to recite “substantial and credible information … that may constitute grounds for an impeachment.” In a section of that report principally authored by then–Starr deputy Brett Kavanaugh, Starr argued that Clinton’s purported efforts to encourage witnesses to lie—including by soliciting Monica Lewinsky to file a false sworn affidavit denying her sexual relationship with the president—merited impeachment, as did Clinton’s efforts to cause others to lie before a grand jury. In a memo he wrote to Starr, Kavanaugh was even more emphatic, asserting that Clinton’s conduct amounted to a “disgrace” to the legal system.

Then-Rep. Lindsey Graham, who served as one of the House “managers” who prosecuted the case for removing Clinton from office before the Senate, also assailed the president for “cho[osing] to manipulate the evidence, the witnesses against him and get his friends to lie” in a civil litigation. But Graham stated that what tipped the scales for him was that Clinton doubled down and continued to lie under oath after his conduct became the subject of a criminal investigation. This, Graham asserted, manifestly constituted a “high crime” that virtually compelled the president’s removal.

That is just what President Trump stands accused of today. While Trump has refused to testify (reportedly because his advisers are convinced he will lie), he now stands accused of directing his attorney to lie under oath to Congress regarding a matter standing at the very heart of an investigation. Furthermore, the investigation concerns a foreign adversary’s attempt to influence the outcome of a presidential election, with implications for national security that are potentially graver than Watergate, let alone Starr’s inquiry into Clinton’s lies about his sexual activities.

As Barr stated to Graham, under the federal witness tampering statute, a person who encourages another to lie under oath bears criminal liability along with the perjurious witness.

Democratic leaders of the House have, quite properly, made it plain that they will not seek to impeach Trump unless they are joined by members of the other party. Twenty years ago, Graham argued that it was important to remove Clinton for lying in the midst of an investigation in order to place the “burden” on the next president not to engage in similar conduct. It now appears likely that Graham will have to decide whether to place that burden on Donald Trump. His answer may determine the president’s fate.