(CBS Local)- Democratic presidential candidate Joe Biden said Monday that he is “not a fan” of court packing when asked about it after a campaign stop in Cincinnati. The term has been in the news a lot over the last few weeks after both President Donald Trump and Vice President Mike Pence challenged Biden and his running mate Kamala Harris respectively on the topic.

With the Senate judiciary hearings to confirm Amy Coney Barrett to the Supreme Court ongoing, court packing only continues to grow as a discussion point. So, what exactly is court packing? Has it been done before? And, how, in theory, would it work?

Let’s take a look through those three questions.

What Does “Court Packing” Mean?

“I think people actually mean a bunch of different things,” said Nicole Hemmer, an historian who currently works associate research scholar with the Obama Presidency Oral History project at Columbia University. “But, the main reference is this idea of stuffing the courts with people who agree with you ideologically or politically.”

The Supreme Court currently has nine justices but that number is not set by the Constitution. Rather, the Constitution only lays out that the Chief Justice shall preside over any Impeachment trials. The size of the court has not changed in the last 151 years. But, it fluctuated between five and 10 justices over the course of the first 80 years of its existence.

“For almost the entirety of the 19th Century, the Supreme Court changed. From a low of five members to a high of ten members, it finally settles on nine members in the late 19th Century,” said Hemmer. “But, Congress has this ability to add or subtract members from the Court. For a long time it was associated with the number of federal circuit courts. If we were still doing that, we would have 13 Supreme Court justices because we have 13 federal circuit courts.”

The severing of that relationship between the number of justices and the number of federal courts occurred in the latter stages of the 19th Century and early 20th when the requirements of circuit riding for justices were ended completely. So, where did the term court packing come from? One particular historical precedent.

“It really traces back to 1937 when Franklin Roosevelt, who was tired of a conservative court returning New Deal legislation, proposed adding a bunch of new justices to the Supreme Court so that he would have a liberal majority,” said Hemmer. “Most of the time, when people say court packing, they are trying to point to that very unpopular politically motivated moment.”

Roosevelt, looking for more favorable rulings when it came to his legislation, proposed the idea of 15 justices on the court. However, that was met with swift backlash and voted down by a 70-20 margin in the Senate.

Has Court Packing Been Done Before?

Court packing, no. Court expansion, yes. The original Supreme Court, established by the Judiciary Act of 1789, established a court of six justices.

In 1807, Congress created the Seventh Circuit to serve the areas of Ohio, Kentucky and Tennessee. With that came a seventh justice on the Supreme Court. After another 30 years, in 1837, with the addition of eight new western states to the union, two more circuit courts were added which then upped the total to the nine justices where it resides today.

Those changes to the court were, outside of a particularly notable instance, mostly made to coincide with new states and therefore new circuits being added. However, the conversation about the court changes over time with a few of its landmark decisions.

“As the court becomes more of an ideological player in the U.S. and recognized as such, things like Brown v. Board of Education was a really important moment,” said Hemmer. “Rulings on school prayer, privacy, abortion, criminal justice, there is more attention to the ideological composition of the court. That’s where you start getting these very serious fights over the Court itself.”

But, the conversation about court packing today, Hemmer points out, is not quite the same as the discussion of Roosevelt’s tactics in 1937.

“In many ways when people are talking about court packing today, they’re talking about it as a remedy to these new conservative justices being put on the court, when at the same time liberal Democrats were denied the opportunity to appoint justices to the Supreme Court. In that case, it seems to match up historically. You want to expand the court to put more liberal justices on,” said Hemmer. “But, in the case of Roosevelt, he was trying offset specific judgments about specific legislation. In this case, Democrats are making more of a procedural argument that they had been denied the normal process of appointing judges and in order to redress that very irregular blocking of Democratic appointed justices, that the Court has to be expanded to re-balance the Court.”

The imbalance of the court, which would turn to 6-3 conservative vs. liberal leaning justices in the case of Amy Coney Barrett’s confirmation, really dates back to 2016 Hemmer says.

At the time, President Barack Obama had nominated Merrick Garland to fill the vacancy on the Supreme Court left by the passing of justice Antonin Scalia. However, Senate majority leader Mitch McConnell refused to hold hearings to confirm Garland saying that, “Of course, the American people should have a say in the court’s direction. It is a president’s constitutional right to nominate a Supreme Court justice, and it is the Senate’s constitutional right to act as a check on the president and withhold its consent.”

When President Trump won the 2016 election, he nominated Justice Neal Gorsuch, who was then confirmed by a mostly party line 54-45 vote with only Democrats Joe Manchin, Heidi Heitkamp and Joe Donnelly voting to confirm.

Now, with weeks to go before the 2020 election, the Trump administration has nominated Amy Coney Barrett. McConnell and the administration have pushed forward with the nomination posing what Hemmer calls a 1-2 punch leading to renewed calls for court expansion.

“I would say the conversation about court expansion is only loosely tied to Amy Coney Barrett. It’s really tied to Merrick Garland and the refusal to give Merrick Garland a confirmation hearing because that was the most out of usual Senate order thing to happen,” said Hemmer. “That but, then I think the 1-2 punch of having that happen and having Republicans making a set of seemingly neutral arguments about ‘oh well we can’t confirm anybody so close to the election,’ and then to have the Amy Coney Barrett nomination come up weeks before an election, the combination of those two is really what I think has given real life, and real possibility to this idea of court expansion.”

How Does/Would Court Packing Work?

So, if a president of either party wanted to expand the Supreme Court, how would they achieve it? In that respect, it’s the same process of any law.

“It’s actually fairly easy to do. It is an act of Congress. It would have to pass by a majority in the House. And, depending on the filibuster rules of the Senate, which have changed or are subject to change, would be subject to a bare majority or a super majority depending on the state of the filibuster. And then signed into law by the President,” said Hemmer.

In today’s polarized environment, that would likely mean that a party would need control of both houses of Congress and the Presidency in order to make an expansion happen. That said, the size of the court and its expansion or contraction, are within the framework of Congress’ duties set forth by the Constitution.