With a reputation for sometimes crossing party lines to help Democrats clear crucial legislation, moderate Sen. Susan Collins (Maine) is perhaps the most unlikely of Republicans to criticize President Barack Obama’s health care reform agenda.

Collins, weeks after Obama was inaugurated, was one of only three Congressional Republicans to support the president’s $787 billion economic stimulus package. But on health care reform, the former state insurance regulator has so far resisted appeals from Obama and Senate Majority Leader Harry Reid (D-Nev.) to come aboard. And, in so doing, Collins has taken a different tack than fellow centrist and Maine Republican Sen. Olympia Snowe.

Republicans close to Collins say they are not surprised, and say health care policy — not the independent political leanings of her state — will likely dictate her vote on any final reform package. They say Collins’ thinking on health care has been shaped by her previous job as state Commissioner of Professional and Finance Regulation, which included oversight of Maine’s Bureau of Insurance.

In another twist, Collins was appointed to that position by then-Gov. John McKernon (R), Snowe’s husband.

“Susan Collins is as conservative a Senator as can be elected from Maine,— a former GOP Senate leadership aide said. “She is wired differently than Sen. Snowe. Susan Collins will over-think every aspect of this, but will do what’s in her gut in the end.—

Given Collins’ concerns with the bills approved by the Health, Education, Labor and Pensions and Finance panels — the latter won a yes vote from Snowe in committee — Maine’s junior Senator might not support the forthcoming Senate floor bill. Reid is charged with producing that final product, a merger of the Finance and HELP bills.

On Tuesday, Collins echoed the most conservative of her Republican colleagues in describing her problems with the legislation. She remains opposed to a public insurance option and said some Mainers change their mind about the proposal after she explains its implications.

[IMGCAP(1)]“Both of the Senate bills would have the unintended but very real effect of actually driving up the cost of health insurance for middle-income families,— Collins said. “That is the opposite of what most people want to have occur, but it’s what I believe would be the result.—

“Neither bill takes strong enough steps to reform the health care delivery system to lower the cost of health care. The cost of health care is the major barrier for the unemployed. It’s the major reason that small businesses and middle-income families are struggling,— she added.

While Snowe is considered a likely player in Reid’s closed-door negotiations on a final Senate bill, Collins indicated that she does not expect to participate. Those talks include Reid, Finance Chairman Max Baucus (D-Mont.), Sen. Chris Dodd (Conn.) — the No. 2 Democrat on Health, Education, Labor and Pensions — and senior White House officials.

But Collins is looking to take an active role once the final bill hits the floor.

She has been holding discussions with Senators on both sides of the aisle, and is working with Sen. Joe Lieberman (ID-Conn.) on amendments to address the health care delivery reforms she believes are essential. Last week, she took a telephone call from Reid, and she continues to receive considerable attention from Minority Leader Mitch McConnell (R-Ky.).

Last month, two days after Obama’s address to a joint session of Congress on health care, Collins journeyed to the White House to discuss the issue with Chief of Staff Rahm Emanuel. Obama dropped in on that meeting, and two nights later, Collins had dinner downtown with White House Budget Director Peter Orszag. She has not talked to anyone at the White House since.

A senior Democratic Senate aide said Tuesday that Collins remains on Reid’s radar for 60 votes to overcome a filibuster of a reform package. Republican Senate aides say Collins has kept McConnell informed of her position from the outset, again noting that she has emerged as one of the loudest voices in private Conference meetings against the Democratic bills.

“She understands the issue very well, she’s been very thorough in her analysis of it and she finds a lot of things wrong with the legislation. I agree with her,— Minority Whip Jon Kyl (R-Ariz.) said. “If [the Democrats] have been listening to what she’s been saying, it would be hard for them to assume that she’s going to necessarily going to be voting to support a big bill like the ones that have come out of the committees.—

Still, Republicans concede that Collins’ vote is in reach, and even she acknowledged as much as recently as last week.

But senior GOP aides believe that in contrast to Snowe, the Democrats will have to make significant changes to the health care overhaul to attract Collins’ support. Collins doesn’t want to appear to be criticizing her Maine colleague, but that alone isn’t likely enough to sway her in the end.

“In the case of the stimulus bill, I was convinced that it was necessary to help create and save jobs and give our economy a boost at a time when we were in the worst recession since the Great Depression,— Collins said. “In the case of health care, we’re talking about legislation that effects 17 percent of our economy. … The implications are enormous. And I believe that none of the bills that I’ve seen so far achieve what I think is the most important goal.—