Have you ever noticed that the gun control advocates focus more on the guns than those who use them? The only time they mention gun owners is when it is politically expedient to accuse them of being members of a conspiracy to profit from the misfortune of others, but even then, they ultimately go back to the idea that the guns themselves are the problem. They rarely even consider the fact that there are criminals.
Attacking leftists on the goals of the gun grabbers will go nowhere. The historical record is plain to everyone on both sides. Then there is the fact that the leftists have turned to guns themselves to fight oppressive (and generally other leftist) regimes. Spain's civil war is a good example. The majority of the anti-Nazi resistance in Europe consisted of communist movements, including the famous Italian and French resistance movements.
Where the left should be attacked is their belief in materialism. If you examine their propaganda, their essays, their books, you will see one thing that every type of leftist believes: that everyone is intrinsically good. From their view, violence only arises from either the deprivation of basic necessities, or the accumulation of too much wealth and power. From their view, the gun itself is a source of power that corrupts those who hold it, by giving them a superiority or even god complex. The worst variants of leftism believe that money is also a source of corruption and would seek to eliminate it despite the slavery that would ensue without a universal medium of trade.
They never see the rapist who would rather force a woman into sex than charm her. They never see the armed robber who would rather steal than earn. They never see the mohammedan who blows up a shopping mall because the Koran advocates the forced conversion of infidels and because the same book advocates the capture and rape of women and theft of the "infidel's" valuables.
They see the rapist as a symptom of the "patriarchy;" if only men were brought down in terms of wealth to the perceived level of women, then they would disappear. They see the armed robber as the desperate man who had no other way to feed his family, or as the troubled man who felt the power of the gun. They see the terrorist as the third worlder who lashed out funding and arming of Israel.
Ironically, this belief has resulted in more violence and destruction than every war combined.