I just wrote a reply on my own blog but I'll comment here as well: I think this is VERY dangerous.
It isn't because I think they will actually secede, but because this is the start of a domestic terrorist ideology.
Whichever Democrats are left who hold any values and love of this country should denounce this RIGHT NOW. Why are they letting this continue? They know what this will lead to. Are they that power hungry that they would see people killed by anarchist bombs in the streets just to blame Bush for it all?
I know that some Democrats are that low, but there must be a few who are not. Look at Zell Miller and Ed Koch - lifelong Democrats who have some sense. And there are others as well. They must stand up and denounce this loudly. If they do not, then I really have no hope for the Democratic party. They are talking treason at this point, and it isn't funny. They can't actually gather a military force to engage in a civil war, but you all know full well what a few nut jobs inspired by this kind of crap can do with some well-planted pipe bombs.
This is incredibly dangerous and it shouldn't be the subject of jokes from the Democratic side. But all we hear from them is silence. That isn't good enough. They need to speak loudly and clearly that this will not be tolerated. As much as they hate Bush, they must not encourage this sort of thing.
You raise an interesting point. The great problem, of course, is that the Democratic party has been purged of the Zell Millers (old-fashioned populist Dems), Henry "Scoop" Jacksons (Dems for a strong National Defense), and - soon - Ed Kochs (Patriotic liberals). The shadow party, made up of hard-core anti-American leftists, controls the whole machine. The folks you call upon to renounce this type of idiocy are much too few now. The voices of reason have been driven out.
Not only are they talking treason now (as you mention), they ran a traitor for president. He gave aid and comfort to our enemies in time of war. The fact that he ended up as the nominee tells us all we need to know about the Democrat party and its intentions for the nation. At the end of the day, there can be no reconciliation with these folks. They despise America and their desire is to transform it - by any means necessary - into a socialist utopia. Absent an opportunity to mold America into their twisted image, they will opt to side with the jihadis in bringing about its demise. The history of the least century should tell any sensible person where such thinking ends up: With mountains of corpses and rivers of blood like those in Russia, Germany and China. An amicable divorce would truly be the best alternative.