Well, now we're getting into one of the fundamental theoretical differences between Marxism-Leninism and Liberalism - namely the former's skepticism and ultimately rejection of the liberal model of democracy as being anything but farcical in nature (at least insofar as there exist multiple class interests in such a society).

Speaking as a Marxist-Leninist, I do not support the preposition that "democracy" is simply a system in which 50% + 1 vote, or a plurality wins in an election every few years between which of a few candidates from nighly identical political parties happened to attract billions in funding (which certainly does not come without strings attached), claim to support the mass interests - and then without exception go on to show the lie to their words. It's almost perversely amusing how, in my native United States, every four years the non-incumbent presidential candidate claims to "change" the fundamental corruption and entrenched corporate interests (which manifests in many forms of harm covert and overt to both working Americans and working people abroad), only to further support such evils. Why? They have the same corporate masters.

The vast majority of media in "democratic" society is controlled by four corporations. Politicians are openly courted by other large corporations.

And let's say for sake of argument there was a candidate who truly cared about mass interests in the United States. Surely such individuals must exist; indeed, I've met many in my years of activism there. Yet as it is structurally set up so that one must almost certainly court the interest of one of two ideologically similar parties and that of corporate donors and corporate media (which certainly does not come without strings attached, compromising of their own ideology), it's effectively impossible for them to rise beyond a blip beyond a radar on the national scene. By design.

It didn't take a particularly long look at things to determine that for all its vaunted "freedom", the United States of America was just as ideologically entrenched and monolithic - by design - as detractors of communism accuse us of being. All states are, as a matter of definition; they are mechanisms to promote the interests of a certain class.

The only difference between communist and liberal states on this matter, really, is that we are generally intellectually honest enough to admit that we are indeed promoting the interests of a single class - the working class. To me, this IS democracy - pursuing the interests of the masses without any chance of political restraint from ideological positions that seek by design to promote oppression or otherwise hold back human progress.

So what does the Marxist-Leninist view of democracy look like? A party which supports mass interest having unrestrained power to do so. Individual members elected in as broad a coalition as possible, with the requisite condition of them having proven their competence and dedication to uplifting the working class. In different Marxist-Leninist nations, naturally, given different historical and cultural conditions, this has manifested in slightly different forms of government, but this is the underlying theory.

The DPRK specifically has re-emphasized Lenin's position that the most intellectually advanced segment of the working class (the "paintbrush" in the "hammer, sickle, and paintbrush") has a duty to uplift the consciousness of the rest of the working class. This manifests both through the state education system (and actually, as early as the 1920s, Communists in Korea were opening schools free of charge to teach literacy, science, history, and theory to Koreans in the countryside; the Japanese government generally made these illegal), and the Korean Workers' Party (which again has 14% membership).

A certain analogy might perhaps be drawn to Plato's Analogy of the Cave for instance. Kim Il Sung himself is quoted as saying that, in the context of a capitalist society, only one in a million will come to the ideological position of socialism on their own, one in a thousand after being taught by the former; the remainder will only change their consciousness during/after the revolution. This creates a "catch-22" of sorts: to build socialism, we require mass consciousness; to have mass consciousness, we require socialist control of the superstructure.

The only posited solution by Lenin was simply that those individuals who DO have such consciousness do whatever they can to spread their message, agitate as much as possible, and eventually provoke such a confrontation with the existing capitalist state in an open revolution that it can no longer be ignored or marginalized. Then, and only then, will the masses, as history has shown, organically mass behind the movement. Farmers and peasants taking up arms in one mass movement against landlords, imperialists, capitalists, and oppressing foreign soldiers is to me, a far more organically democratic movement than putting "George Bush" or "Barack Obama" (either as the "lesser of two evils") on some piece of paper every few years, then going back to the latest reality show.

Communism is by definition a mass movement. Every Communist nation on earth was birthed by one, and if they falter too much in their duty of promoting proper consciousness to the working class masses (as was the case in late USSR), it is ultimately their death knell.

Ultimately it comes to the question of whether or not one supports empowering the masses and abolishing capitalism (which I find to be the moral equivalent of abolishing slavery). If so, they are my ally, and I hope them to have as much power as possible so that my goals may more expediently be reached; if not, they are an impediment to human progress, as I see it, and ought to be suppressed via whatever means necessary (again, as stated in early posts, peacably if possible).

So returning to your initial question, I don't see "free speech" when it comes to advocating a position that is, in its own terms, harmful to mass interests as being pro-democratic; but by very nature anti-democratic (as it is seeking to remove power from the masses). Imagine for instance, what a better world we might have lived in, if, to take your own example, the US Federal Government had simply rounded up and imprisoned all former plantations owners following the Civil War (perhaps on charges such as high treason for having participated in the CSA's war effort?)? If they had banned the Democratic Party for its support of slavery and illegal terrorist organizations such as the White Camelia and the KKK? If they had imposed strict curfew, rounded up the White Camelia/KKK members, publicly exposed and punished them? If the Weimar Republic had not put a bullet in the brain of Hitler and the rest of his Brownshirts when they had them imprisoned, how much suffering might have been averted?

Again I'd propose as peaceable methodology feasible in suppressing reactionary movements, but at the end of the day, I recognize them as movements seeking goals I feel to be deeply harmful to members of my fellow human species (as you yourself admit in regards to the American South), and as such, any means necessary to suppress individuals openly trying to harm the interests of the working class are, to me, justified. It's not as if anti-communist regimes haven't used such methods against us when it was tactical; we're just generally more intellectually honest that, as supporters of the interests of the working class, we don't tolerate those actively seeking to harm them.

While I dispute some of the unsourced details of your claims, to be honest, I don't have particularly much more sympathy for someone actively trying to disrupt a socialist state than I do for a Neo-Nazi or KKK member. Anyone opposed to the liberation of mankind is ultimately an enemy of our entire species. I don't consider myself a particularly violent person by nature (ironically, I got into a lot of this ideology in the first place through the anti-war movement); I see violence as an absolutely last resort; I'd prefer simply resettling them to their own autonomous ideological communities; but if it ultimately comes to a question between taking out a few reactionaries or allowing them to win and bring back a system of repression that allows the rich to grow richer through exploiting the labor of the poor that propagates itself through imperialism, I'll take out the reactionaries in a heartbeat. To me, democracy is about putting the mass interest above ALL other concerns - certainly including "freedom of speech" or "freedom of association" to self-admittedly harmful movements.