I don’t think it’s a stretch to say that, in recent years, the battle over Supreme Court nominations has gotten pretty contentious. That’s at least in part because the stakes are so high.

"This is the most important position that a president can give out — I think we can say — by far," said President Trump at a news conference in September. "I’ve actually heard it’s the most important decision a president can make."

This is, in large part, because the tenure for a Supreme Court Justice is unlimited. In my quest to understand why, I turned first to James Madison’s "Notes of Debates of the Federal Convention of 1787." Here, Madison relates the moment the framers got the judicial ball rolling in Philadelphia. For the record, it was on a Monday in June.

"On [the] motion to agree to the first clause, namely " resolved that a National Judiciary be established, "it passed in the affirmative nem. con.," wrote Madison.

Nem. con. is an abbreviation for a Latin phrase that means “without dissent.” So, while the delegates unanimously agreed there would be a national judiciary, deciding what it would look like, and what it would do, would take some work. One place where there was quick consensus, with little if any debate, was that lifetime term in office for justices.

"They’re following a precedent from Great Britain, which was followed by most but not all of the states, which is the idea of tenure during good behavior," said Harvard Law Professor Michael Klarman, author of "Constitutional Convention."

Klarman said the reason for that lifetime appointment was simple: To cultivate judicial independence. If you never have to worry about being re-elected or re-appointed then, "there’s no reason to tailor your decisions to the pleasure of the institution that does the appointing," Klarman said.

As for which institution would do the appointing? That proved a bit more controversial.

"They agreed, provisionally, early in the convention, that the appointments power would be vested in the Senate," said Klarman.

But this was before a compromise between the large and small states that gave all of them equal power in Congress's upper chamber, with two senators a piece. Large states felt they’d have more sway over who became president, so they began to favor shifting powers, like appointing judges, to the executive branch.

"It was very much a function of, not really which institution in some ideal sense was better equipped to make the appointment," he said. "It was mostly an argument about power."

And so, another compromise was struck: The president would appoint, but the Senate would have to approve.

As for the actual role of the court, Klarman said the framers saw a venue where, say, one state could sue another, or an English creditor could sue an American farmer and get a fair shake.

As for its role in interpreting and determining the constitutionality of laws passed by Congress and the states, Klarman said that, too, was expected.

"But nobody would have contemplated at the time that the Supreme Court would play such a large role in resolving political and social disputes," he said. "And the Supreme Court wasn’t resolving them 200 years ago."

But Klarman said in recent decades — whether it be gun control, affirmative action, campaign finance regulation, the death penalty, or health care — it has become expected that the ultimate outcome of contentious issues will rest with the Judiciary.

"That’s just a very different kind of judicial function than they were anticipating 200 years ago," he said.

Back in the mid-19th century, a backlash against the idea of judges with lifetime appointments swept across America. Today, some 38 states elect judges, and nearly all states have some limit on the lengths of a judge’s term.

"I think that the same thing would have happened at the federal level if it were not so difficult to amend the Constitution," said Klarman.

Of course, with elected judges — or limited terms — comes a whole other set of benefits and drawbacks. And while it is difficult to amend the Constitution, it is by no means impossible. The framers might not have been able to foresee the SCOTUS of the 21st century, but they knew the Constitution they were drafting would not be perfect. And left it to future generations to decide what — if anything — might make it more perfect.