THE DIFFERENCE BETWEEN NEEDING A VOTE AND NOT…. The more aggressive Howard Dean became in fighting to kill the Senate health care bill, the more the White House communications operation pushed back. By yesterday afternoon, Robert Gibbs told reporters, “I don’t think any rational person would say killing [the health care reform] bill makes a whole lot of sense at this point.”

Now that Sen. Ben Nelson (D-Neb.) is threatening to kill the bill altogether, Jed Lewison asks if the conservative Nebraskan will “get the Howard Dean treatment.”

So here’s a question: Will the White House come down as hard on Ben Nelson as they have on Howard Dean?

I’ve seen this come up in a few places today, but I think it’s extremely unlikely that the White House will be even mildly, indirectly critical of Nelson — but it’s not because the president’s team is somehow playing favorites or coming down harder on liberals.

The truth is, this week, we’ve seen some progressive senators — first Roland Burris, then Bernie Sanders — make fairly explicit threats, too, and the White House didn’t say a discouraging word about them, either.

The difference is, the White House doesn’t need Howard Dean’s vote — he doesn’t have one in Congress. The administration does need Nelson, Burris, Sanders, and every other member of the Senate Democratic caucus to vote for cloture.

Now, one could make the argument that harsh public criticism of these senators might intimidate them and make them more likely to go along with the reform agenda, but I suspect that the opposite is likely true — if Robert Gibbs started trashing Ben Nelson from the briefing room podium, any chance Dems had of picking up his vote would quickly disappear.

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.