Washington (CNN) Supreme Court Justice Elena Kagan extolled the late Justice John Paul Stevens and decried the effects of partisan gerrymandering on democracy. Yet it was not until a student at the Georgetown Law forum on Thursday asked about Spider-Man that Kagan began gesturing excitedly.

Her response to a question about a 2015 patent dispute over a toy glove that could shoot "webs" revealed at once Kagan's rhetorical flair and, more importantly for today's Supreme Court, her regard for precedent.

Kagan has become a powerful voice of the liberal wing, trying to counteract the conservative majority in the fight over whether to preserve court milestones. She achieved two surprising victories on that front in the recently completed session.

And even as she dissented in perhaps the most consequential case of the term -- which prevents judges from halting extreme partisan gerrymanders -- Kagan delivered a statement from the bench that was arguably her most passionate of a near-decade tenure.

The 2010 appointee of President Barack Obama is the junior-most among the four justices on the left, yet she has become one of the more intriguing of the nine to watch. She is readier than her colleagues, including senior liberal Ruth Bader Ginsburg, to move to the middle of the ideological spectrum to strike deals to keep the court centered.

With the Spider-Man question, Kagan, 59, brought together much of what matters to her in stabilizing the law, even as she showed her whimsical side.

"I read Spider-Man as a kid," she said of her youth in Manhattan, adding that she wanted to keep up with a brother who was "a big comic-book aficionado."

She recalled that the toy in the patent-royalties dispute could emit pressurized string foam. She pretended she was pulling on the glove device. "Then you went like this," she said, flinging out her hand before the audience, "and webs came out."

"If you can't get a Spider-Man reference into a case like that," Kagan quipped, "you're not working hard enough."

But, Kagan emphasized, as much as it was a delight to write, Kimble v. Marvel Entertainment was, primarily, "a case about stare decisis." And in upholding a 1964 patent rule, she turned a Spider-Man refrain into a Supreme Court ideal.

"(I)n this world, with great power there must also come -- great responsibility," she wrote, quoting Spider-Man, in 2015. On Thursday, she reiterated her belief that, "We have the power to overrule cases, but we have the responsibility to use that power" sparingly.

As demonstrated during oral arguments and in multiple recent opinions, that has become her mantra

"We take it super-seriously," she said in a March session regarding the possible reversal of precedent. "I mean, we used to -- and we need a good reason for it."

Precedents on the line

With the addition of two appointees of President Donald Trump, the high court has signaled a greater willingness to reverse decades-old precedent. Liberal Justice Stephen Breyer implicitly warned in a May dissent, as the five conservatives tossed out a 1979 precedent in a California tax case, that landmarks such as the 1973 Roe v. Wade, which made abortion legal nationwide, could be at risk in the future.

In another dispute, in which the same five justices on the right led by Chief Justice John Roberts, rolled back property-rights precedent, Kagan said the court "smashes a hundred-plus years of legal rulings to smithereens."

She observed that Breyer had wondered in the May tax dispute "which cases the Court will overrule next." She answered in her June opinion, " Well, that didn't take long . Now one may wonder yet again."

Yet in two of the most closely watched cases of the session, testing power in the executive branch, Kagan pulled out narrow majorities to keep in place much of existing precedent.

With the fifth vote of conservative Justice Samuel Alito, Kagan wrote a decision in Gundy v. United States declining to reconsider Congress' delegation of authority to executive branch agencies, for example, to regulate public safety and protect the environment. Rounding out the majority were Ginsburg, Breyer, and Kagan's fellow Obama appointee Sonia Sotomayor.

Then, with partial support from Roberts, Kagan drew a bare majority to rebuff much of a challenge to two key precedents shielding agency authority. The new ruling in Kisor v. Wilkie retained considerable judicial deference for administrative agencies interpreting their regulatory scope.

Conservatives are especially skeptical of agency authority over individual and business activities. Justice Neil Gorsuch, among the dissenters in both Gundy and Kisor, referred in the latter to "the explosive growth of the administrative state over the last half-century."

Gorsuch and fellow Trump appointee Brett Kavanaugh have laid down markers that demonstrate the battle over federal regulation is just heating up.

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Calls the gerrymandering ruling 'abysmally wrong'

The ideological clash over partisan gerrymandering , however, climaxed in the recent term. Roberts led a five-justice majority to a decision that federal courts could not take up challenges to voting district maps excessively gerrymandered to entrench the controlling political party.

While Roberts acknowledged that "excessive partisanship in districting leads to results that reasonably seem unjust," he concluded that such challenges to it present political questions that should stay out of the federal courts.

As she took the rare step of reading portions of her dissent from the bench on June 27, the last day of the term, Kagan said the court majority had abandoned its duty to protect American democracy.

"I didn't really pull my punches about the importance" of the decision to America's political system, she told the Georgetown audience on Thursday.

"There's no part of me that's ever going to become accepting ... of a decision ... that essentially (says) that the courts shouldn't get involved in gerrymandering no matter how bad it is, no matter how destructive of our political system it is," she said.

She added that she would put the decision in Rucho v. Common Cause in a category of "abysmally wrong" rulings. Yet Kagan, a former Harvard law dean and US solicitor general, said she was "100% certain" the majority reached the decision in good faith.

On Thursday, she reserved her highest praise for the man she had succeeded in 2010, Justice Stevens. She described him as humble, respectful and "sharp as a tack" until his death at age 99 this week. She noted that he was taking daily swims in the ocean nearly until the end: "He seemed to all of us -- eternal."

Stevens had told her that he took stock at the end of every annual session. "He tried to think every term about all the things he could learn the next term," he said, expressing admiration for a jurist who never felt "that the time for apprenticeship was over."

For her part, Kagan later told the audience that she hoped her dissent against partisan gerrymandering lived on.

"You're writing a dissent because you want to convince the future," she said, adding that she had a message for advocates beyond the courts who might work for political reform: "Go for it -- because you're right."