(Reuters) - U.S. Senator Susan Collins of Maine, a moderate Republican who helped block her party’s efforts to repeal the Affordable Care Act this year, said she planned to remain in her current office rather than run for governor.

The four-term incumbent attracted national attention this summer as one of three Republican senators who voted in July against a bill to repeal the law often called Obamacare, a move that angered U.S. President Donald Trump. She said on Friday that remaining in the Senate would allow her to use her powerful voice in reforming the U.S healthcare system.

Collins, who like all Republicans in the Senate in 2009 voted against the sweeping healthcare legislation, said she believed urgent action was needed to improve it but criticized the way repeal efforts had been handled over the summer.

“When we’re dealing with an issue that affects millions of Americans, we need to understand the consequences of what we are doing, not vote on bills in the middle of the night that have had no substantive hearings,” Collins, 64, told a group of business leaders in Rockland, a city on the state’s midcoast.

“We must stop allowing partisanship to be the pre-existing condition that prevents meaningful healthcare reform.”

Urgent action is needed to stabilize the insurance markets, including creating high-risk pools, she said. She wants to require employers to offer healthcare coverage only to people who work 40 hours a week or more, raising the threshold from 30 hours.

For weeks, Collins had flirted publicly with the idea of launching a bid to succeed Governor Paul LePage, a fiery conservative first elected in 2010 on a wave of support from the populist Tea Party movement. State laws forbid LePage from seeking a third term.

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Collins and LePage mark out the two poles of the state’s Republican Party.

Collins’ independence makes her an increasingly powerful player in Washington, one veteran Maine political observer said.

“She is at the very center of virtually every big policy debate and big vote in the U.S. Senate,” said Mark Brewer, professor of political science at the University of Maine. “She remains an incredibly important player on any issue she wants to focus on.”

Senate Majority Leader Mitch McConnell welcomed the news: “Her decision to remain in the Senate is important not only for the people of Maine, who she serves so well, but for the nation as a whole.”