BRUNSWICK — It is time for Sen. Susan Collins to prove she is a moderate and an independent Mainer. In the wake of the Republican disaster on health care, she told The New York Times that “with the demise of the House bill, there’s a real window of opportunity for a bipartisan approach to health care.”

While it is not clear what she means by that, it is a real opportunity for her to show Mainers and the nation that she is not a typical Republican and is prepared to improve the Affordable Care Act and not dump it over the side, tossing elderly and low-income Americans with it.

But first, she needs to prove she is truly independent. One good way to start would be for her to forgo any future campaign donations from any health care group, trade association, insurer, pharmaceutical manufacturer or other health sector political action committee – funding on which her last re-election campaign heavily depended.

A careful review of the most recent campaigns of Maine’s four federal elected officials shows that Collins’ campaign was by far the most highly dependent on PAC contributions from associations and businesses in the health sector.

A careful review of the campaign financing disclosures of Collins, Sen. Angus King and Reps. Bruce Poliquin and Chellie Pingree reveals that Collins ran an expensive campaign, depending significantly on PAC funding, with PACs in the health sector being the heaviest hitters of all. Consider the following:

• Collins ran the most expensive campaign of all four elected officials. In the 2013-14 cycle, when she ran for re-election, her campaign contributions from all sources (individuals and PACS combined) came to $5.1 million. Poliquin’s 2015-16 re-election campaign ($3.3 million – a pretty expensive sum for a House race), King’s 2011-12 Senate campaign ($2.87 million) and Pingree’s 2015-16 re-election bid ($613,000 – pretty inexpensive) raised significantly fewer funds.

• Collins raised more funds from PACs – $2.14 million – than any of the other three. Poliquin came close, at $1.74 million; King trailed significantly at $460,000, while Pingree came in dead last at $171.000.

• Collins depended significantly on PACs for her campaign funding – 42 percent of her total contributions came from PACs. (Poliquin depended even more on PAC money, at 52 percent of his total.) Pingree, at 28 percent, and King, at 16 percent, were significantly less dependent.

• Collins was significantly dependent on campaign contributions from health-sector PACs. All told, 146 PACS in the health sector contributed $531,100 to her re-election, which was nearly 25 percent of her total PAC funding. No other economic or professional sector came close to providing as large a share of her funding.

• By contrast, 9.4 percent of Poliquin’s campaign funds, or $165,000, came from the health care sector (he scored bigger with the PACs of fellow members of Congress and especially those funny-named right-wing groups and the Koch brothers). The health sector provided 9.4 percent of Pingree’s PAC funds, as well, but that was a grand total of $16,000. And they provided 19.8 percent of King’s PAC funds, a measly $91,500.

Many of these PACs are the heavy hitters in the for-profit health business (Abbott Labs, Aetna, Amgen, Bayer, Eli Lilly, Genesis Healthcare, Humana, McKesson, Novo Nordisk and Pfizer, for example); insurers (such as Aetna, Anthem-Wellpoint, Liberty Mutual and Primerica), and trade associations that promote the interests of medical practitioners (the American Medical Association, the American Hospital Association, the American Society of Anesthesiologists and many, many more).

These contributions were most certainly legal. And they carry weight. These are the companies and groups most highly interested in an American health care system that costs each American more than twice as much as that of any other industrial country, and gives them the worst outcomes in much of the industrialized world, according to the Commonwealth Fund and the Organization for Economic Cooperation and Development.

They have funded and promoted the resistance to significant health care reform that could guarantee high-quality care for all Americans at an affordable price. We owe the problems of the Affordable Care Act and the train-wreck that was the Republican alternative (the American Health Care Act) to these barons of the health sector, in addition to the politicians they fund.

To be a true independent, Collins needs to separate herself from their funding. She should announce today that she will no longer accept PAC contributions from any company, association or other group in the health sector until Mainers and the rest of America finally have the health care they deserve.