"The point is that I can say good things about something, but I can't say bad things about something," she said. "And I would have thought that that was a fairly classic case of viewpoint discrimination."
The Oregon-based band says the 70-year-old law violates free-speech rights. A federal appeals court had ruled that the law is unconstitutional, but the government appealed.
A victory for the band would be welcome news for the Washington Redskins, embroiled in their own legal fight over the team's name. The trademark office canceled the football team's lucrative trademarks in 2014 after finding the word "Redskins" is disparaging to Native Americans.
But the justices also seemed concerned that imposing absolutely no limits on trademark names might go too far.
At issue is a law that prohibits registration of marks that "may disparage ... persons, living or dead, institutions, beliefs or national symbols." A trademark confers certain legal benefits, including the power to sue competitors that infringe upon the trademark.
Slants founder Simon Tam says his goal was to reclaim a derisive slur and transform it into a badge of ethnic pride. But the trademark office said a term can be disparaging even when used in a positive light. A federal appeals court sided with the band, ruling that the law violates the First Amendment.
The Obama administration wants the high court to overturn that ruling. Justice Department lawyer Malcolm Stewart told the justices that the law does not restrict speech because the band is still free to use the name even without trademark protection.
Stewart said the government was concerned about allowing trademarks for racial slurs, religious insults and the "vilest racial epithets" that distract consumers and hinder commerce.
Justice Stephen Breyer wasn't impressed, saying he could think of "perhaps 50,000 examples of instances where the space the trademark provides is used for very distracting messages."
"What business does Congress have picking out this one, but letting all the other distractions exist?" Breyer asked.
Justice Anthony Kennedy compared the trademark program to copyrights, noting that the government can't bar disparaging copyrights.
"We have a culture in which we have T-shirts and logos and rock bands and so forth that are expressing a point of view," Kennedy said. "They are using the market to express views."
Justice Ruth Bader Ginsburg said the law wasn't being enforced consistently, noting that the term "Heeb" was approved in one trademark application, but not in another. The term is considered offensive to Jews.
John Connell, attorney for The Slants' founder, said the First Amendment should allow trademark approval of virtually any expression without limits. But some justices seemed to think his argument went too far. The trademark law, for example, places restrictions on words that are libelous or cause confusion in the marketplace.
"You want us to say that trademark law is just like a public park" where people can say whatever they want, Kennedy told Connell. "Goodbye. That's it. That's your argument."
Justice Sonia Sotomayor wondered about libelous trademarks. What if someone tried to register "Trump is a thief" before the president-elect became a public figure, she asked.
Connell said that should be allowed.
"That makes no sense," Sotomayor said.
Breyer noted that The Slants are free to use their name in all kinds of ways, just not in the trademark itself.
"This is not a general expression program," Breyer said. "It stops nobody from saying anything."
Like The Slants, the Redskins say their name is meant to honor American Indians. But the team has spent years fighting legal challenges from Native American groups that say it's a racial slur. A federal judge upheld the trademark office's cancellation of the name and the team is appealing. The matter is on hold pending the outcome of the Slants case.
A ruling in that case is expected by the end of June.
Following Wednesday's hearing, Slants founder Simon Tam released this statement:
I'm confident that the Supreme Court will stand by the Court of Appeals for the Federal Circuit's decision in finding viewpoint discrimination through trademark registration unconstitutional.
What many people forget is that this process all started with the government denying me rights based on my race: even in court, the government agreed that our racial identities provided the context for "The Slants" to be a racial slur rather than any other possible definition for the word. In other words, the government alluded that anyone could register "The Slants" if they had the right context - or in this instance, if they were of the right race. That's simply wrong. It perpetuates institutional racism.
I've spent almost 8 years in court - almost a quarter of my life - so that I could fight for marginalized communities to have their voices protected. Voices that are often silenced in fear of a football team regaining their trademark registrations. Our obsession to punish villainous characters should not justify the collateral damage that the undeserved experience. Part of taking up the cost was possibly being forever associated with a team who I find disagreeable, but it was for the greater good of justice. Being the target of both white supremacist groups and even a few organizations that normally support my work will all be worth it if it means a more equitable society.
I hope that our case encourages others towards having robust conversations of racial justice in order to create better law.