On Friday, the House Judiciary Committee approved two articles of impeachment against President Trump on a party-line vote. The president has derided the articles as “impeachment lite,” and some Democrats have bemoaned the articles’ narrow scope.

But the articles are more significant than they may at first appear. How are these like — and unlike — impeachment charges from the past or crimes prosecuted in a court of law?

1. The past is present in these articles.

The first article of impeachment accuses Trump of violating his oath of office by soliciting a foreign power, Ukraine, to interfere in the U.S. 2020 presidential election. The three previous times Congress moved toward impeaching a president, the articles also focused on violating the oath of office.

That’s not surprising. The presidential oath is unique among the U.S. oaths of office: The president must preserve, protect and defend the Constitution of the United States. Legislators and civil servants merely “defend and support the Constitution.” The oath is the officeholder’s promise to focus on duty to country and the constitutional system. When the president fails to do so, legislators must “defend and support” what he attacks.

President Andrew Johnson’s articles of impeachment repeatedly referred to the oath, claiming he failed to “preserve, protect, and defend the Constitution” when he removed Secretary of War Edwin M. Stanton — thereby breaking a law that Congress had passed over the president’s veto. In doing so, the articles charged, Johnson had violated his oath.

The House was about to impeach Richard Nixon for violating his oath when he tried to cover up the fact that his office organized a break-in at the Democratic National Committee’s Watergate offices. The articles prepared before his resignation claimed that by covering up illegal actions, he failed to “execute the Office of the President” — seeing that the laws are “faithfully executed.” Similarly, when President Bill Clinton perjured himself over an affair with an office intern, thereby “willfully corrupting and manipulating the judicial process,” the House charged that he was acting against his oath.

2. The focus on harm to national security is novel — and hard to prove.

The first article also charges that when Trump asked Ukraine’s newly elected president to announce an investigation into Trump rival Joe Biden, he was soliciting foreign interference in the 2020 election — and identifies that as an impeachable offense. The article argues that to pressure Ukraine to deliver, Trump withheld both congressionally approved military aid and a meeting at the White House with Ukrainian President Volodymyr Zelensky.

In doing so, the articles argue that Trump compromised national security. That focuses on the president’s essential role in the U.S. system. Besides executing the law, the framers expected the executive branch to act as the first line of defense against attack, both at home and abroad. This unique constitutional role belongs to the branch that can act quickly and decisively, which is why the oath includes a “protect” clause.

But proving that Trump ignored or injured national security may be difficult. The United States has a broad scope of interests internationally. A president has many legitimate avenues for seeking to protect those interests.

The articles also charge that Trump undermined the democratic process — that he “betrayed the nation by abusing his high office to enlist a foreign power in corrupting democratic elections” and “acted in a manner grossly incompatible with self-governance and the rule of law.” Once again, proving that a president has betrayed the nation is hard. By contrast, the “smoking gun tapes” clearly proved Nixon had tried to cover up the Watergate break-in. And testimony showed that Clinton had perjured himself to a federal grand jury when denying his affair with an intern.

3. Obstructing Congress is unlike obstructing justice.

The second article charges that the president told his subordinates to defy subpoenas issued by the House as it pursued its constitutionally protected “sole Power of Impeachment.” That charge of obstruction of Congress assumes that the institution’s power to investigate is also constitutionally protected.

In recent years, Congress and the presidency have often had a highly fractious and politically polarized relationship. At times, some observers believed that Congress’s efforts to oversee the president’s actions have been an opposition party’s political tool to embarrass or harass a sitting president. For instance, after the 2006 election, Republicans lost both houses of the legislature. President George W. Bush’s defense secretary, Robert Gates, later wrote that once the Democrats took over, “it was impossible to have a sensible discussion … on anything to do with Iraq in the presence of television cameras.” Similarly, in the Benghazi hearings that began in 2014, Republicans investigated Secretary of State Hillary Clinton’s alleged failures before and after an attack on the U.S. Embassy in Libya.

Others argue that even if it looks politically charged, investigations are part of Congress’s constitutional obligation to ensure that executive power is used appropriately. The Supreme Court has held that such efforts are essential for ensuring Congress can legislate. Congress started investigating the executive branch’s actions as early as 1792, after Native tribes in the Northwest Territories inflicted heavy casualties on U.S. troops. While the Trump administration is challenging several congressional subpoenas in court, Republicans argue that Congress’s oversight powers have limits that must be determined by the court — and that until the courts determine these limits, the president can’t be charged with obstructing Congress.

Obstruction of justice has clearer rules, worked out in the courts over centuries to prohibit actions that undermine the rule of law. In focusing on obstruction of Congress rather than justice, Democrats imply that when the executive obstructs congressional oversight, the president damages the proper functioning of the rule of law in much the same way as refusing to testify in court undermines the justice system.

In the end, impeachable conduct is whatever a House majority declares it to be. Whether the Senate agrees is another question entirely.

Sarah Burns (@sarahmackenzieb) is associate professor of political science at Rochester Institute of Technology, fellow at the Quincy Institute, and author of “The Politics of War Powers” (University of Kansas Press, 2019).

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