Sen. Susan Collins said Wednesday it would be entirely within bounds to ask President Donald Trump’s upcoming Supreme Court nominee whether the landmark Roe v. Wade decision on abortion is “settled law.”

“Absolutely,” Collins said during an interview with News Center Maine. “And I’m glad you asked that question because it’s been a lot of misunderstanding.”

“What I am saying is that a nominee’s personal views on Roe v. Wade are not relevant to my decision,” Collins said. “What is relevant is whether they’re committed to longstanding precedent.”

The Maine Republican, whose support of Trump’s nominee will likely prove critical to confirmation of the lifetime appointee to the nation’s court, repeated Wednesday that she would not comment on support for potential candidates.

“How can you ask me to take a position on a nominee whose identity I don’t yet know?” she asked.

Collins was speaking at a Fourth of July parade in Bangor, where she faced pressure from constituents across the political spectrum. Separately, the abortion rights group NARAL began running online and print ads in publications across the state of Maine on Thursday.

That advertising campaign, directed at Collins, asks whether or not she believes past statements by the president signaling he could seek to appoint justices that would upend the Roe v. Wade precedent. It was visible on the website of the Portland Press Herald on Thursday morning.

A NARAL-sponsored automated poll from Public Policy Polling released Thursday said some 63 percent of Pine Tree State voters do not want the Supreme Court to overturn Roe v. Wade. The PPP findings echo a national poll that found similar numbers across the country.

Trump has said he plans to announce his nominee to replace the retiring Anthony M. Kennedy on Monday.