For House Democrats, there is a powerful temptation to narrow the grounds for impeachment. By adhering to a simple narrative about President Trump’s criminal actions in relation to Ukraine, they hope it will be easier to mobilize public support than if they levied a more complex set of charges.

In the impeachment of Richard Nixon, the Democratic-controlled Judiciary Committee faced a similar choice. Despite significant dissent, the committee ended up limiting itself to three articles of impeachment, all connected to the domestic crimes of Watergate.

But as House committee chairmen begin the process of drawing up articles of impeachment, it is worth considering that its findings and their scope will reverberate through time. Long after the next election, they will condition how Americans look upon this period of our history and what correctives might be found.

For Nixon’s impeachment, there was actually a fourth article of impeachment. It encompassed more serious offenses and incited intense debate among the members. Introduced by Representative John Conyers of Michigan, it charged the president with “the submission to the Congress of false and misleading statements concerning the existence, scope and nature of American bombing operations in Cambodia in derogation of the power of Congress to declare war, to make appropriations and to raise and support armies.”

With regard to Cambodia, the illegality of Nixon’s behavior was clear-cut. The potential fourth article of impeachment referred to the fact that for 14 months, before the United States’ invasion, the president approved hundreds of B-52 strikes on that country. The covert mission first came to light in July 1973, when retired Maj. Hal Knight testified before the Senate Armed Services Committee that in his capacity as the supervisor of radar crews in South Vietnam, he had helped falsify the records of at least two dozen missions by disguising American airstrikes in Cambodia as attacks inside South Vietnam.