U.S. Sen. Susan Collins. R-Maine, said Sunday that the Senate will face a tough ethical question if Roy Moore wins the special election Tuesday in Alabama for the seat formerly occupied by Attorney General Jeff Sessions.

In an appearance on the CBS News talk show “Face the Nation,” she also said she is waiting to see the final version of the Republican tax reform plan before she decides whether to support it.

Collins said she is disappointed the Republican National Committee resumed its support last week for the scandal-plagued Moore, who faces allegations of sexual misconduct with teenage girls.

“I think that is a mistake,” said Collins.

She said she never supported Moore’s candidacy even before the allegations surfaced, because of his positions against Muslims, LGBT rights and his two-time removal from the Alabama Supreme Court. Collins said Republicans care as much as Democrats about stopping sexual misconduct and she has joined a group of senators who are reviewing Capital Hill procedures to address the subject.

Collins said the Senate will face a difficult decision on whether to try to remove Moore from office on ethical grounds if he is elected to the Senate. She said it is a different situation when sexual misconduct allegations surface against someone already in office than when they are made against a candidate who then goes on to win in spite of the allegations.

“If the allegations are known prior to the election, then we have a very tough decision to make about whether it is our role as senators to overturn the will of the people,” she said.

Commenting on tax reform legislation, Collins repeated concerns she raised last week about the competing House and Senate bills.

Collins has become a regular on the Sunday news talk show circuit this year because she wields critical swing votes on health care, tax cuts and other issues. She also sits on the Senate Intelligence Committee, which is investigating Russian interference in the 2016 presidential election and possible collusion between the Trump campaign and Russia.

A conference committee is currently trying to reconcile the differences between the House and Senate versions of the tax reform legislation. Collins, who voted for the Senate bill, said she will not decide on whether to support the conference committee’s bill until she sees the final proposal. She said the commitments she received from Republican leadership and President Trump to support her amendments to the Senate tax bill, such as the retention of medical expense deductions, will be honored and approved.

She also said she is confident the bill will not contain cuts to Medicare.

“I have written correspondence (from the Republican leadership) that memorializes the agreement that the cut that could go into effect will not go into effect. I don’t want seniors to have the anxiety that the tax bill will trigger a cut in Medicare,” Collins said on “Face the Nation.”

Maine’s senior senator also said she has had repeated commitments from the Republicans and Trump that the Affordable Care Act’s cost-sharing payments, which are made to insurers to help hold down co-payments and deductibles for low- and middle-income people, will be retained.

“I have talked with the president three times on this issue. I have no reason to believe that commitment will not be kept. Who wants to see health insurance premiums become more unaffordable than they are?” said Collins.

Despite Collins’ optimism surrounding the Republican tax plan, her constituents back in Maine continue to criticize her position.

There have been three protests since last Monday at or inside her offices in Bangor and Portland, and several people, including nine members of the Maine clergy, have been arrested and charged with criminal trespass. The unrest over her support of the plan surfaced again Sunday in front of her house in Bangor.

About 20 protesters stood outside her home during a peaceful demonstration. No one was arrested, but organizer Clare Mundell of Bangor said the protests will continue until Collins withdraws her support of the Republican tax plan.

Mundell said the group she belongs to, Indivisible Bangor, has tried on several occasions to persuade Collins to hold a town hall in Bangor, but without success. According to its Facebook page, Indivisible Bangor is a group of Bangor-area residents who resist the Trump agenda.

“We figure if she won’t come to us, we’d go to her,” Mundell said.

Staff Writer Dennis Hoey contributed to this report.