Moderate Senate Democrats uncomfortable with Majority Leader Harry Reid’s (D-Nev.) health care reform plans are coalescing around Sen. Olympia Snowe and are looking to the centrist Maine Republican to provide them political cover at home and viable policy alternatives on the floor.

Reid’s bill remains largely under wraps pending a Congressional Budget Office analysis. But moderate Democrats — particularly those representing conservative-leaning states — are nervous about what they do know. They are pushing to replace Reid’s public insurance option proposal, which includes an opt-out provision for the states, with Snowe’s plan for a public option “trigger— — preferably before any floor debate on health care reform begins.

On Tuesday, moderate Sen. Mary Landrieu (D-La.) made clear she supports Snowe’s proposal for a public insurance option that would only be triggered in the future if private insurers failed to adequately lower health premiums. Sen. Ben Nelson (D-Neb.), a leading centrist, confirmed that the moderates were continuing to meet with Snowe to strategize a way forward that brings the Republican on board and softens Reid’s bill.

“There’s a possibility that that could occur,— Nelson said. “Right now, we don’t know what the actual version of the plan is because it hasn’t come back from CBO. … My expectation is that it probably doesn’t have enough to get 60 votes to get off the floor if it gets on the floor.—

Added Sen. Tom Carper (Del.), another leading centrist: “I think we as Democrats will rue the day if we don’t find a thoughtful way to make sure that Sen. Snowe’s central premise, perhaps modified … finds a home in the legislation that we finally vote on.—

Democrats, Carper warned, should not “turn our back on— Snowe, particularly after she “stood with us against her entire caucus, against a lot of very nasty people across the country, and had the courage and the conscience to vote with us and report a bill out of the Finance Committee.— Delaware’s senior Senator was candid in acknowledging that courting Snowe’s vote could pay political dividends.

Among the Senate’s moderates, Snowe carries weight as a thoughtful legislator and a talented deal-maker. Additionally, she is seen as among the chamber’s most-educated Senators on health care policy. But a Democratic Senate aide who works for a moderate conceded that there also are several practical considerations that account for Snowe’s popularity.

[IMGCAP(1)]Democratic moderates believe that Snowe’s vote could bring Sen. Susan Collins (R-Maine) aboard, and possibly a third and fourth Republican as well. And for Democratic Senators such as Blanche Lincoln (Ark.) who are facing the prospect of a tough re-election in 2010, Snowe offers the hope of political cover from a public not sold on the Democrats’ health care agenda.

“More broadly, Snowe and other moderate Republicans may be key votes on future pieces of legislation,— this Democratic aide said. “Keeping them close to the vest will make passing future bills easier.—

Snowe confirmed Tuesday that conversations with moderate Democrats are ongoing, but she would not discuss the details of those talks.

Some Democratic centrists view Snowe’s trigger proposal as a viable alternative should Reid’s public insurance option with opt-out fail to garner 60 votes. These moderates believe the proposal could replace Reid’s public option down the line, after the floor debate is well under way. Carper has been floating to centrists the notion of modifying Snowe’s trigger to include a way for states to voluntarily opt in to a public or nonprofit option.

But Snowe believes her proposal doesn’t stand a chance if it is not inserted into the bill before the debate begins. Snowe, conceding the unlikelihood of Republican support for the proposal, predicted that liberal Democrats would also oppose it, making it exceedingly difficult to secure the 60 votes needed both to strip Reid’s proposal and insert hers.

“Essentially, in a lot of ways, we share the same underlying concerns about a public option and so we sort of, I think, reflect those concerns — those mutual concerns,— Snowe said, when asked why she has become such a key figure for moderate Senate Democrats.

With a majority of Democratic Senators in favor of the public insurance option, Reid went with a version of the policy that he believed put him in the best position to secure 60 votes. The robust public insurance option, modeled on the version approved by the Health, Education, Labor and Pensions Committee, was designed to appeal to Democratic liberals; the opt-out clause for the states was added to attract the support of the moderates.

However, several centrists have expressed deep skepticism with the proposal, leading Reid and his leadership team to burn the phones and use personal time lobbying these Senators in an effort to determine what it will take to get their votes to get on — and then off — the bill.

Finance Chairman Max Baucus (D-Mont.), who was one of two Senators to join Reid at the negotiating table to draw up the Senate bill, had previously pushed for a nonprofit medical cooperative, insisting for months that the public insurance option could not earn 60 votes. Baucus lauded Reid’s decision to go with a public option with an opt-out clause, but he conceded Tuesday the measure could run into trouble.

“I did for a long time think that the public option could not get 60 votes. I don’t know. I mean, this is evolving, it’s changing,— Baucus said. “There are several Senators [who] as you know have voiced concerns about it, and I don’t know where they’re going to end up.—