Elena Kagan was the type of student who could both thrill and scare a professor when she raised her hand in class.

Augusta native Richard Fallon, who’s taught constitutional law at Harvard Law School since 1982, would know.

Kagan, President Obama’s choice to take the place of retiring Supreme Court Justice John Paul Stevens, enrolled in Fallon’s “The Federal Courts and the Federal System” class as a Harvard Law student in the 1980s.

When her hand shot up, “I knew what she was going to say was going to be superbly insightful,” Fallon said. “There would be a little wobble in my knee, too, because sometimes the very best students can put to you questions and challenges you don’t have fully adequate responses to.”

Kagan, who earned her Harvard Law degree in 1986, went through Fallon’s class early in his Harvard tenure.

Thirteen years later, Kagan became Fallon’s colleague when she joined the Harvard Law faculty in 1999. After that, she was Fallon’s boss during her time as law school dean from 2003 to 2009.

If confirmed, Kagan would be a “superb justice,” said Fallon, who was the 1970 Cony High School valedictorian.

“She’s tough in just the way you would want a Supreme Court justice to be,” he said. “When she’s made up her mind about what she thinks is right, nobody is going to bully her out of it. I think that’s exactly what you want in a Supreme Court justice.”

That toughness is a quality Kagan — currently the U.S. solicitor general — displayed as Harvard Law’s dean, Fallon said.

“She’s very smart, very deliberative, listens to all sides of arguments before she makes up her mind,” he said. “And then when she makes up her mind, she’s very decisive. I suspect those traits will all carry over.”

As researchers, politicians, journalists and others scour Kagan’s background for hints about her judicial philosophy, many have brought up her management of military recruiting on campus.

An outspoken opponent of the U.S. military’s “don’t ask, don’t tell” policy that prohibits gay men and lesbians from serving openly, Kagan banned military recruiters from campus in 2004 after a Philadelphia appeals court found the Solomon Amendment, which allowed the federal government to withhold funds from campuses that prohibited military recruitment, unconstitutional. Kagan lifted the ban in 2005.

She faced criticism from gay and lesbian advocacy groups for not taking a stronger stance. From conservatives, she faces criticism for her public opposition to the military’s “don’t ask, don’t tell” policy.

“The position that she took was actually pretty moderate. I don’t mean to be denying she took a stand of principle; she certainly did,” Fallon said. “She didn’t make it impossible for military recruiters to get in touch with Harvard students. She always made clear that she supported and was proud of those Harvard students who chose to serve in the military.”

Kagan critics are also pointing out she’ll be a rarity among current justices for never having served as a judge.

But that shouldn’t count against her, Fallon said.

“I don’t think it ought to be an absolute requirement that nobody can serve on the Supreme Court who hasn’t been a judge of a lower court,” he said.

In fact, only in recent decades has it become common for Supreme Court justices to have prior judicial experience, Fallon said.