As the Senate takes the first procedural vote Saturday on health care reform, I thought we should run down the procedural situation that Senators find themselves in.  It's not simple.

First, this vote is not like the vote two weeks ago in the House on health care reform.

That was on an entire bill.

This vote is basically whether debate should officially start on health care.

And to be 100% accurate about it, the Senate is not even voting to start work on a health care bill.

"Huh?" you say?

The Senate is voting on the Motion to Invoke Cloture on the Motion to Proceed to H.R. 3590, the Service Members Home Ownership Tax Act of 2009.

That means, the Senate is voting to shut off debate on the motion to start debate on the underlying bill.

Instead of using the House-passed health care bill, Democrats are using a bill that was already approved by the House - which raises money - so it doesn't violate the Constitution's requirement that all money bills originate in the House of Representatives.

Once the Senate officially starts debate on H.R. 3590, then the real fun begins, as Democrats will offer the text of the changes put together by Sen. Majority Leader Harry Reid as a substitute amendment to that bill.

That will start the real battle.  Sen. Reid will probably file the first amendment to the substitute, and control amendments procedurally from there.

He might even "fill the amendment tree" - but let's not get too far ahead of ourselves.

This is step one.   On what we refer to as "The Deuce" (C-SPAN2) it will read:

"Motion to Invoke Cloture on the Motion to Proceed to H.R. 3590, the Service Members Home Ownership Tax Act of 2009."

Don't forget, the Democrats need 60 votes today.  Anything less, and all hell breaks loose.