THE ‘CENTRISTS’ BLOCKING THE DOOR…. Senate Majority Leader Harry Reid (D-Nev.) will, in about an hour, unveil his health care plan to the Democratic caucus. Soon after, Reid is expected to talk about his proposal with reporters.

But a select few received a sneak preview this afternoon.

Democratic Sens. Blanche Lincoln, Mary Landrieu and Ben Nelson, who have all expressed skepticism about the party’s health care reform plan, were summoned to Senate Majority Leader Harry Reid’s office Wednesday to get a sneak peak at his health care bill.

Reid spokesman Jim Manley said Wednesday the senator invited these three moderate Democrats into his office to give them the “particulars on the bill.”

All have been withholding support on voting to start debate — and the fact that Reid is giving the three their own special briefing, before the broader Democratic meeting at 5 pm Wednesday, is a signal of their power.

In case you’re thinking that this list of center-right Dems is missing someone, keep in mind that Joe Lieberman has already said he’ll vote for the motion to proceed — putting Nelson, Landrieu, and Lincoln to the right of Lieberman.

And just to clarify further, Reid is wooing these three, not to vote for the bill, and not to cut off a Republican filibuster of the bill, but just to get their support to send the legislation to the floor for consideration. To that extent, this is almost ridiculous — three Senate Democrats are seriously thinking about joining Republicans in blocking a debate on health care reform. Forget an up-or-down vote, Nelson, Landrieu, and Lincoln have to be pleaded with just to allow the Senate to talk about health care reform on the floor.

If it seems hard to imagine an actual Democratic senator going so far as to strangle health care reform in the crib, note that CNN’s report added that Landrieu said “she is leaning toward a ‘no’ vote on the motion to proceed.”

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.