I spent some time on the phone earlier today with aides to Mike Johann and Ben Nelson and it turns out there's very little ambiguity: Johann's motion would have resulted in a budget that all-but-froze non-defense discretionary spending, and two high profile Democrats supported it.

Here's how it would have worked.

If the motion had passed, it would have sent the Senate budget back to Sen. Kent Conrad's budget committee with instructions for them to design a new budget which shaped and shrunk proposals in such a way that total non-defense discretionary spending would have grown at an inflation-indexed pace for five years. Inflation is currently very low. Johann's website says, "[u]nder this amendment, spending in FY 2010, would have grown at 1.2% as opposed to the proposed 9% increase.

To highlight the scale of the proposal, when Kent Conrad introduced his budget last month, he called for a seven percent increase in non-defense discretionary spending from 2009 to 2010. That would have increased budget authority from about $490 billion to about $525 billion. Under a budget shaped by Johann's motion, that $35 billion increase would have shrunk to about $5 billion. That's not a spending freeze per se, but it's pretty close.

A spokesman for Ben Nelson says, "Senator Nelson voted yes on Senator Johanns' motion to recommit the budget resolution and instruct the Budget Committee to limit discretionary spending increases to CBO's projected rate of inflation for each of the budget years."

Late update: There's another issue worth highlighting here, too. Bayh and Nelson opposed the Democrats' budget because it was supposedly too profligate. But the two of them nonetheless joined eight other conservative Democrats in a successful effort to pass an amendment that raises the estate tax exemption from $7 million to $10 million and lowers the top rate from 45 percent to 35 percent. The cost of the amendment? About $250 billion.

Perhaps it will be removed in conference.