Last week, Chief Justice John Roberts appeared before the Senate and took a solemn oath. Then he requested that the assembled senators do the same. “Do you solemnly swear,” he asked, drawing upon the chamber’s rules, “that in all things appertaining to the trial of the impeachment of Donald John Trump, president of the United States, now pending, you will do impartial justice according to the Constitution and laws, so help you God?” The senators collectively murmured their response: “I do.”

The Senate will spend the next few weeks seated placidly in their chamber, unable to speak or move for hours at a time each day. They will be compelled to listen as House managers lay out the case that President Donald Trump betrayed the country. The House’s de facto prosecutors will describe in detail what the evidence that is already available shows: Trump orchestrated a scheme to coerce a foreign power into smearing a potential 2020 opponent, and endeavored to do everything he could to prevent Congress from uncovering the plot.

Trump’s legal team has reportedly “dismissed the validity of both articles of impeachment lodged against him,” but it remains unclear what it will offer in defense beyond this tacit rejection. The president’s frenetic tweets and public statements make it hard enough for fervent loyalists to defend him on television, let alone before the U.S. Senate. If his lawyers deny the allegations outright, they will be asking senators to vote in favor of their own stupidity. If they admit Trump’s wrongdoings but claim it doesn’t justify his removal from office, they will be asking senators to vote in favor of joining a corrupt plot against American self-government. Trump himself is on trial, but so are the 100 senators who must pass judgment against him.

Throughout the trial, both sides will draw upon the founding era for guidance about whether Trump’s actions merit his removal from office. In a way, the Constitution’s drafters anticipated this moment. At the time, Britain’s House of Commons had the power to impeach officials, while the House of Lords had the responsibility to conduct impeachment trials. During the Constitutional Convention, the power to impeach naturally fell to the House of Representatives. But handing the power to conduct trials to the Senate did not come as easily as it may seem.

In the Federalist Papers, Alexander Hamilton concluded that there was no workable alternative. Creating an ad-hoc tribunal out of nonfederal officials for each impeachment would add too many risks and complications, he wrote. Foisting the responsibility upon the Supreme Court would also be ill-advised. Hamilton feared that the unelected justices might not always possess the “credit and authority” in Americans’ eyes to remove presidents and other high officials from office, making their judgments “dangerous to the public tranquility.” What’s more, an impeached official could still face criminal trials and punishments after their removal from office. “Would it be proper that the persons who had disposed of his fame, and his most valuable rights as a citizen in one trial, should, in another trial, for the same offense, be also the disposers of his life and his fortune?” he asked.