The Senate set the wheels in motion on repealing the Affordable Care Act with a 51-48 party-line vote early Thursday, with Maine’s senators splitting their votes.

Republican Sen. Susan Collins voted with party leadership to start the complicated process of repealing President Obama’s signature health care law, while independent Sen. Angus King, who caucuses with Democrats, voted no. The repeal process is moving quickly, despite talk among Collins and others to slow it down.

“I don’t understand this unseemly haste,” King said in a phone interview with the Press Herald on Thursday.

Mainers want to keep many of the provisions in the ACA, according to a survey of 1,300 Mainers released on Thursday by Public Policy Polling. Sixty-three percent of Mainers surveyed last week said they wanted to keep what works with the ACA and fix the law’s flaws, while 32 percent favored repealing the law and starting over with a replacement.

While Collins sided with fellow Republicans on the vote, she was one of the first Republicans calling to decelerate efforts to repeal the law, to allow for a replacement plan to be written and potentially voted on at the same time. After the November election, Republican leaders initially advanced a “repeal and delay” strategy, where the ACA would be gutted but Congress would give itself two to three years to devise a replacement. But starting in early December, Collins criticized “repeal and delay,” saying it could cause insurance markets to collapse and leave many without health insurance.

That sentiment had appeared to gain traction in recent weeks with other Republicans who were reluctant to repeal the law without a way to ensure that the 20 million people with ACA insurance would not lose coverage.

In the end, however, only Kentucky Republican Rand Paul voted against repeal.

The uninsured rate in the United States has declined from 17.1 percent in 2013 to 10.9 percent in the third quarter of 2016 as a result of the ACA.

Collins, as one of a handful of moderate Republicans, holds a key vote in shaping the future of the ACA. If all Democrats held together, it would take three Republican defections to stop repeal efforts.

King said Thursday’s vote was “preliminary” and was the first of many to come about the ACA’s future. He believes from his conversations with Collins and her public statements that she won’t vote for any plan that results in stripping away coverage for thousands of Mainers and millions nationwide.

“I truly believe she understands what’s at stake and wants to find a solution,” King said. “My sense is that there are a number of Republicans who are unseasy with this accelerated process and the prospects of the damage and harm that can be done to people by taking away their health insurance.”

President-elect Donald Trump and House Speaker Paul Ryan have said this week that replacement plans are in the works, although none has yet been introduced.

While a repeal can be accomplished with a simple majority vote in the House and Senate, a replacement plan would need 60 votes in the Senate, meaning the cooperation of at least six Democratic senators. There are 52 Republicans in the Senate, 46 Democrats and two independents, King and Sen. Bernie Sanders of Vermont.

About 80,000 Mainers have marketplace insurance through the ACA, which offers subsidized benefits available to people who can’t get insurance through an employer – often the self-employed or part-time workers.

A Collins spokeswoman released a statement that Collins submitted to the Senate.

“There is growing understanding that we cannot simply repeal the Affordable Care Act now, and then wait two or three years to put reforms in place,” Collins said. “Doing that would risk harming consumers who rely upon the current system for their insurance and would exacerbate the turmoil in the insurance markets.

“If we want a smooth transition from a broken and unaffordable system to a system that finally delivers on the promise of reform, we must carefully plan how we intend to get from where we are today, to where we need to be tomorrow.”

An amendment supported by Collins and four other Republican senators to slow down the process was dropped when the senators were assured that a date to craft the repeal – Jan. 27 – could be changed at any time, Collins’ statement said.

Collins, while arguing for caution in replacing the ACA, noted that she opposed the law and that one negative consequence of it is dramatic premium increases on the health insurance marketplace.

“In Maine, premiums on the (marketplace) will rise an average of 22 percent this year, and many states are seeing even higher premium hikes. Meanwhile, fewer insurers are willing to write policies, leaving few choices for consumers who are looking for insurance,” Collins’ statement said. “Some of the ACA’s provisions – especially its consumer protections – enjoy bipartisan support and should be retained; however, its Washington-centric approach must be changed if we are ever to truly reform our broken health care system.”

While the premiums are rising, the increases are absorbed by the subsidies for those who qualify for assistance – about 85 percent of those purchasing insurance on the marketplace. But those who don’t qualify for subsidies bear the full brunt of the premium hikes.

King said he’s willing to work with fellow lawmakers to fix the law, but saw no reason to start the repeal process.

Emily Brostek, executive director of Consumers for Affordable Health Care, an Augusta-based health advocacy group, said she was “disappointed” in Thursday’s vote, but still hopeful the ACA could survive.

Brostek said the law is popular in Maine, and while final enrollment numbers aren’t in yet, sign-ups for 2017 are on track to surpass last year.

“I would hesitate to predict what’s going to happen to the ACA, because it changes from day to day,” Brostek said.

Deborah Deatrick, senior vice president of community health at MaineHealth, the parent company of Maine Medical Center, said the implications of repealing the ACA are far-reaching and harmful. She said it’s not only that people wold lose health insurance, but for example hospitals would see a dramatic increase in people using emergency rooms for care and in uncompensated care. Those developments would increase costs in the system and result in price hikes in private insurance.

“I am nervous about it, but I am hopeful there’s a recognition that we can’t just repeal the ACA without a suitable replacement,” Deatrick said.