The essence of the Murtha plan to end the war involves budgetary restrictions on how money can be spent towards the war effort.
As it is budgetary in nature, a budget bill including Murtha-provisions will not be subject to Senate filibuster. Yes, Murtha's plan can pass the Senate with 51 votes, however much the other 49 don't like it.
How's that you ask? Here we have the magic of the Byrd Rule.
Basics of the Rule
First off, this thing is actually a law and not just some arcane piece of Senate procedure. It was originally an amendment by (who else) Senator Robert Byrd (D-WV) to a bill passed in 1985, and made permanent in another act passed in 1990.
As law, it actually applies to the House too, but since House rules give the majority more power anyway, it is currently moot, as the House Majority can achieve the same result without invoking the Byrd rule (I suppose if the House ever adopted Senate like rules, then it would be germane again).
So, on to the best part, from Wiki:
Reconciliation is a legislative process of the United States Senate that is intended to allow a contentious budget bill to be considered without being subject to filibuster.
What's "reconciliation" you say?
Reconciliation is an expedited process under the 1974 Congressional Budget Act used to change mainly entitlement and revenue laws in order to implement budget resolution policies. Although reconciliation is an optional process, Congress has used it in most years, beginning in 1980, as its principal deficit-reduction tool. In recent years, it also has been used to advance tax cuts. The Senate adopted the Byrd rule in 1985 as a means of curbing extraneous matter in reconciliation measures.
(Source)
Ok, so like you, my thought was: Sure, but this is intended only to expedite passing the ever vital budgets, so that the trains keep running on time. There's no precedent for using this on something as contentious as ending the Iraq war right?
Hello, Pre-emptive strike on Republican Hypocrisy:
Until 1996, reconciliation was limited to deficit reduction, but in 1996 the Senate adopted a precedent to apply reconciliation to any legislation affecting the budget, even legislation that would worsen the deficit. Under the administration of President George W. Bush, Congress has used reconciliation to enact three major tax cuts. Senate Republicans have repeatedly tried to use reconciliation to open the Arctic National Wildlife Refuge to oil drilling.
Well, well, well. 1996 you say? To quote noted extremist Glenn Reynolds aka "Instapundit": "Heh."
Not only that, but it serves as a salve to some of our wounds about the perceived weakness of our Democratic senators during those years. Why didn't they stop this crap? Partly because they were fighting an uphill battle against the rules.
Are there Limits to this?
Frankly, yes. This isn't a cheap-out whereby you can pass a Net Neutrality bill as a budgetary measure just by burying a provision to spend $1 or something. The measures can only be objected to on these 6 grounds:
(1) produce no change in outlays or revenues (e.g. authorizing language, findings, sense of the Senates -- anything that doesn't score);
(2) produce changes in outlays or revenues that are "merely incidental" to their non-budgetary components;
(3) produce spending increases or tax cuts and the net effect is that the reporting committee fails to achieve its reconciliation instructions;
(4) would cause a net spending increase or tax cut in any year beyond the years covered by the reconciliation bill (this year, beyond fiscal year 2005);
(5) are not within the jurisdiction of the reporting committee; or
(6) contain recommendations with regard to Social Security.
And the key is, that upon raising a Byrd-rule objection to a part of a reconciliation bill, it takes 60 votes to sustain that measure as part of the bill.
And finally, the le mot juste:
Debate on reconciliation legislation is limited to 20 hours. Amendments receive 2 hours of debate equally divided; second-degree amendments receive 1 hour of debate equally divided. Time spent reading and voting on amendments is not counted toward the 20- hour total. After time has run out, Senators can continue to send amendments to the desk for votes, but there will be no debate on them.
So that's the key. The ultimate reason why Congressional Democrats can't pass a non-binding concurrent resolution, but they can pass effective and meaningful limits on Iraq spending as part of the budget.
Did I get this right, fellow arm-chair parliamentarians?