As a young lawyer in the Reagan White House, John G. Roberts Jr. was tartly dismissive of the Supreme Court’s long summer break, which stretches from the end of June to the first Monday in October.

“Only Supreme Court justices and schoolchildren,” he wrote in 1983, “are expected to and do take the entire summer off.”

On the other hand, the young lawyer wrote, there is an upside to the break: “We know that the Constitution is safe for the summer.”

These days, members of the court find time to quarrel about the Constitution even in the warm months. The primary antagonists lately have been Justices Samuel A. Alito Jr. and Elena Kagan.

Last summer, they clashed over whether decisions like the one eliminating the constitutional right to abortion threatened the court’s legitimacy.

In recent months, the two justices have continued to spar, though on a different subject: whether Congress has the constitutional authority to regulate aspects of the court’s work.

The question is timely, of course, as news reports have raised ethical questions about, among other things, luxury travel provided to Justices Alito and Clarence Thomas. Those reports have led to proposed legislation to impose new ethics rules on the court.

Justice Alito, in an interview published in The Wall Street Journal last month, appeared to object, saying that “Congress did not create the Supreme Court.”

He added: “I know this is a controversial view, but I’m willing to say it. No provision in the Constitution gives them the authority to regulate the Supreme Court — period.”

A few days later, at a judicial conference in Portland, Ore., Justice Kagan took the opposite view, though she cautioned that The Journal had not reproduced the question that had prompted Justice Alito’s answer. She indicated, graciously, that he could not have meant what he seemed to say.

“Of course Congress can regulate various aspects of what the Supreme Court does,” she said, ticking off a list of ways in which lawmakers can act. Congress sets the court’s budget. It can increase or shrink the size of the court, and it has over the years done both. It can make changes to the court’s jurisdiction.

Indeed, the Constitution provides that the court has appellate jurisdiction “with such exceptions, and under such regulations as the Congress shall make.”

All of this is unsurprising, Justice Kagan said.

“It just can’t be that the court is the only institution that somehow is not subject to any checks and balances from anybody else,” she said, adding, “I mean, we are not imperial.”

On the broader question of whether Congress may regulate some aspects of the court’s activities, Justice Kagan seemed to have the better of the argument. She did not offer an opinion on the narrower question of whether Congress may impose a code of ethics on the justices, but she said the court remained free to act.

“Regardless of what Congress does, the court can do stuff,” Justice Kagan said, adding, “We could decide to adopt a code of conduct of our own that either follows or decides in certain instances not to follow the standard codes of conduct.”

In remarks at an awards ceremony in May, Chief Justice Roberts said that work remained underway. But he added it was a job for the court, not Congress.

“I want to assure people that I am committed to making certain that we as a court adhere to the highest standards of conduct,” he said. “We are continuing to look at things we can do to give practical effect to that commitment, and I am confident that there are ways to do that consistent with our status as an independent branch of government and the Constitution’s separation of powers.”

It was not clear, though, that consensus among the justices was on the horizon, Justice Kagan said.

“It’s not a secret for me to say that we have been discussing this issue,” she said. “And it won’t be a surprise to know that the nine of us have a variety of views about this, as about most things. We’re nine freethinking individuals.”

Congress has enacted laws that apply to the justices, including ones on financial disclosures and recusal. In a way, the most telling ethics legislation came from the first Congress, in 1789, requiring all federal judges, including Supreme Court justices, to take an oath promising “that I will administer justice without respect to persons, and do equal right to the poor and to the rich, and that I will faithfully and impartially discharge and perform all the duties incumbent on me.”

If Congress can take all of those actions, it would seem to be free to enact a code of ethical standards, Amanda Frost, a law professor at the University of Virginia, wrote in a 2013 law review article.

“The Supreme Court is not an isolated institution intended to operate entirely free from the political branches — to the contrary, it has always depended on the political branches to lay out the parameters governing its exercise of judicial power,” Professor Frost wrote, adding, “Congress’s authority over judicial ethics is less surprising once one realizes that Congress has long assumed the power to regulate many important aspects of the court’s daily activities.”