Republicans have threatened all out war in order to block Democratic efforts from reforming the filibuster. But it turns out the real obstacle to changing the Senate rules may be Democrats themselves.

The problem: Some Dem Senators are leery of changing the filibuster via the "constitutional option," i.e., a rules change by a simple majority. In one sense, it's apt that this is what is driving their reluctance: After all, what these Senators are really doing is reinforcing a status quo in which there is no longer majority rule in the Upper Chamber.

The Hill reports this morning that senators Dianne Feinstein, Mark Pryor, and Carl Levin are uncomfortable with a simple-majority change. Senators Max Baucus and Jack Reed have yet to be persuaded. Senators John Kerry and Jay Rockefeller say they're undecided but leaning towards a change. Senator-elect Joe Donnelly is uncommitted. Presuming Republicans vote unanimously against any changes, if Harry Reid loses six votes, filibuster reform is toast.

Look, caution about changing the rules is understandable, particularly with something as dramatic as the constitutional option. But let's put this as simply as we can: We cannot continue with the Senate remaining as dysfunctional as it is. This situation was forced upon Democrats. No matter how many times Republicans insist otherwise, recent GOP obstructionism is simply unprecedented, not just in degree, but in nature. Republicans adopted a deliberate party-wide strategy of grinding Senate business to a halt -- on even routine matters -- with the goal of denying Obama bipartisan successes, pinning the blame on him for ineffective government, bolstering the GOP's anti-government ideology, and rendering Obama a one-term president. Surely that is worse than adopting a set of modest changes designed to prevent excessive and deliberate obstructionism for its own sake -- even if those changes are adopted by (gasp!) majority vote.

And one last time: The reforms Dems are pursuing would not take away the minority's ability to filibuster legislation on the motion to end debate. The minority would still be able to thwart the majority's will if the minority really deemed it necessary. All the changes would do is make it harder for the minority to gum up the works with the explicit purpose of making governing harder for the majority, rather than expressing the minority's will.

Some of the Senators opposing reform say they are more comfortable changing the rules by the traditional two-thirds majority. But that isn't going to happen. We shouldn't allow a minority of the Senate to dictate that we must preserve a status quo that enables that same minority to continue exploiting the rules to render the Senate dysfunctional and less democratic. Presumably those reluctant about reform would concede that at some point, there has to be some accountability for what's happened in the Senate in the last four years.

* More cracks in the GOP anti-tax wall: As noted here yesterday, the White House's aggressive opening fiscal bid represents a big bet that the GOP will have to fold on high end tax rates -- and a sign that Obama is prepared to push the GOP very hard to make it happen. Here, from Senator Olympia Snowe, is the latest sign it may be working:

Moderate Senator Olympia Snowe said she'd consider higher taxes on the wealthy if there was a carve-out for small business owners. "That's more of a possibility if it's going to help resolve some of the questions about getting revenue and getting entitlement reform," she said.

Now if someone can nail down that Snowe means she's open to higher tax rates on the wealthy, that would be getting somewhere. As always, though, what really matters is what the Republicans are willing to vote for in the end, not what they say now.

* GOP divided over whether to stall Obamacare implementation: A very interesting development: In red states, Republicans are fighting over whether to accept the reality of Obamacare and implement the law, or whether to continue doing everything they can to block implementation. It's worth reiterating that the Obamacare dead-enders are explicitly relinquishing control over what happens in their states to the federal government -- which will implement the exchanges if they don't -- in the name of states' rights!

* Same sex marriage before the Supreme Court: It looks like the Supreme Court is set to hear a challenge to the Defense of Marriage Act this week. Tom Goldstein has a good summary of why this will be so profound and momentous -- it goes to the core moral question of whether government can "prohibit a loving couple to marry, or to refuse to recognize such a marriage."

* Why GOPers want Dems to go first on Medicare: As you know, Republicans want Dems to propose Medicare cuts before they do. David Firestone offers an explanation why: Republicans don't have a coherent vision of the program's future beyond transforming it into a voucher scheme, which is to say, undermining its fundamental mission. The other problem for Republicans is simply that Medicare is a government program that has proven successful and wildly popular.

* Yes, Dems have already agreed to major spending cuts: Despite GOP claims that Dems aren't serious about cutting spending, Jonathan Cohn reminds us that Dems already agreed to massive cuts in 2011, and even without adding the new cuts proposed in the White House opening bid, that already brings discretionary spending as a share of GDP "down to its lowest level since early 1960s."

As Cohn notes, the final fiscal deal will likely have still more cuts than the ones the White House already proposed, making the overall trend lopsidedly unbalanced in the direction of cutting spending -- not, as GOPers claim, in the direction of over-spending.

* Senate Dems more unified behind Obama's agenda? Ron Brownstein makes an essential point: In nearly every major 2012 Senate race, victorious Dems won by uniting the Obama coalition behind themselves -- which means they have a strong incentive to stand behind the Obama agenda, even in purple or red states.

I'd only add here that the influx of real and effective progressives will pull the Dem Senate caucus to the left, further solidifying it behind the policies and priorities Obama ran on. And let's hope this applies to filibuster reform, too.

* Does Social Security add anything to the deficit? Much to the pleasant surprise of liberals, Dems have insisted on keeping Social Security out of the fiscal cliff talks, because -- as you will frequently hear them say -- Social Security doesn't add anything to the deficit. Glenn Kessler has a useful overview of that talking point and how it's a bit more complex than it first appears.

* And the fiscal cliff battle is really a class war: Paul Krugman details the bigger story underlying the fiscal cliff talks: Proposals like raising the Medicare eligibility age and raising revenue on the rich only through cutting loopholes, not raising rates, are essentially stealth bids to maintain inequality under the guise of deficit reduction. In this telling, the real battle in this election was one pitting the interests of the rich against those of the middle class and poor -- and despite the verdict, those who bet big on Mitt Romney are still fighting for their desired outcome.

What else?