HARRISBURG — Pennsylvania Supreme Court justices had plenty of questions Wednesday for the attorneys who represent judges challenging a constitutional provision that requires them to retire once they turn 70.

The high court heard oral arguments in a pair of cases that could affect them personally, as several members of the court are nearing that age. But to throw out the retirement age, they will have to rule the provision violates another section of the constitution, one that prohibits age discrimination.

Bart Delone, a lawyer with the state attorney general’s office who defended the retirement mandate, said ruling one element violates another would be unprecedented.

“This court, as far as we can tell, has never done that,” Delone told the justices. “No American court, so far as we can tell, has ever done that.”

Robert Heim, a lawyer for three judges who sued over the mandatory retirement, said the “Declaration of Rights” that comprises Article I of the state constitution lists rights that predate the constitution and therefore cannot be invalidated.

“These are preexisting rights that are inherent to mankind,” Heim said. “They are independent of the constitution.”

Justices noted there is a way to amend the constitution, which requires approval by the Legislature and voters. Some expressed doubts they had the power to do so themselves.

“That’s a pretty drastic step for the courts to take, to take that away from the people,” said Justice Debra Todd.

Heim said people have the right to change or abolish their government, but that should not apply to the natural rights listed in Article I.

“We don’t give people ultimate power under our system of government,” Heim argued, saying the framers of the state constitution were sensitive to the possibility that the majority could become tyrannical.

William Hangley, a lawyer for the judge in another legal challenge, said the retirement age was put in to the constitution for four reasons: to address mental infirmity that sometimes arises after age 70, to put more judges on the bench, to fall in line with what other states do and “to spare the unpleasantness of determining whether or not a particular judge is disabled.”