Hi Kariann,
I'm skipping over the other responses to avoid any possible ongoing arguments, as these threads tend to attract.
I don't think the answer is quite 'why don't dems/libs like guns,' but rather, it's more of a demographics correlation, and the comparisons are between urban and rural communities. Each community has different needs and resources, which shape values and priorities. In rural areas, there's more emphasis on independence and self sufficiency, and it's partly because with less population, there's less civic infrastructure to help the people. It's where we get the argument that an armed civilian could be the safer response than a police dept who may not have the power to arrive to a scene in time.
Conversely, a denser population necessitates a greater civic infrastructure- so in the above example, is less necessary to have an armed civilian, since police response would be more immediate. And with greater populations, comes a greater chance of other civilians being victimized, and greater aversion to civilians carrying weapons.
So where do political allegiances come into this? It's another study of demographics. The needs of those in urban areas usually gravitate towards liberal values, and the needs of a rural community trend conservative. And each is valid in their argument, which makes gun control so difficult to properly study and argue for one side, in general terms. But the short answer to your question- it's not that all liberals hate guns. It's just more likely they come from a community where their availability creates a catastrophic problem.
I hope this response makes some sense. Apologies for not being able to link to anything... I'm on my phone, on vacation, browsing Susan's because I can't sleep :p