Looking at this from an artistic perspective.
It's a bit of a mess and far too cluttered, which makes it difficult to read. The first thing that stands out is the "the only businesses guns are good for are funeral homes and grave diggers"; the stroke effect is far too heavy for that font (which is easily apparent on the "A", "N" and "H", where parts of the font almost disappear behind the stroke entirely); I'd suggest both reducing the stroke size and making it an outer stroke rather than an inner stroke (although that may mean you have to change your kerning). I'd also change the stroke colour; because the background is fairly dark to begin with the black stroke is often too vague (especially over the deep red). I'm not particularly sold on the font choice to begin with but it's a minor issue compared to the others.
Looking at the framing in general, the "explanation" text outside the map is far too close to it which contributes to the cluttered feel. I'd extend the frame, move the main title outside the map and move the rest of the text further away. The explanation of the map ("The deeper the red, the more blood spilled by guns") doesn't stand out which means that at a glance it's difficult to tell what the map actually shows. At the very least it should have a different font and not seemingly be attached to the line above. Personally I'd probably include a "scale" showing what each colour represents (i.e light red = w-x deaths, deeper red = x-y, deep red y-z) and try to make it look more like an "official" document.
The spots highlighting the number of deaths have the same issue that the black stroke does; they blend in and are thus difficult to read, let alone pick out. At the very least they need a change in font colour and a bigger dot then the ones that are currently there. Personally I'd likely move them outside the map itself and then use lines/arrows to connect them to the states in question. They're an important part of the poster because they're the only thing that gives context to the colours (without them something being blood red may still only mean that 10 people in the last decade have died due to guns in that state, it's just that only six people died in a lighter coloured one) but they're not prominent or easy enough to read.
This point sort of straddles the artistic/debate line but the section on child deaths is disjointed from the rest. From the framing it looks like it's meant to be explanatory text of the map... but the point about child deaths is largely seperate to anything else on the map inself. At the very least I'd frame it off in a separate section. It also suffers somewhat because of what you've chosen to highlight elsewhere; you've used big scary numbers previously ("more than 9.4 million dead")... compared to 9.4 million deaths 85 is a very small number and so it loses its impact. Perhaps it would be worth comparing it to something else; i.e in 2010 X children under five died from (insert something people are scared their children might die from but is less than 82).
Focusing on the debate side of things more the big issue is that the map doesn't really say anything of interest. Saying that bigger states have more guns then smaller states and states with more guns have more deaths due to guns is self-evident to the point of ridiculousness. Moreover, for something that's meant to be selling the virtues of gun control it doesn't say anything about gun control, just population size; a heavily populated state where a low percentage of deaths are caused by guns (presumably due to gun control) may well still have more gun deaths than a much less populated state with far more lax gun control laws. Nothing on the map tells me why gun control is a good thing, why we should have more of it or how it would prevent gun deaths... if anything it says the opposite as the "bigger states have more guns" line indicates that gun control is irrelevant to the number of deaths and the best bet to protect myself and my family is to move to a smaller state.
The numbers used on the map have no context and so become meaningless. More than 9.4 million deaths is a big scary number... but what does it mean? More than 9.4 million deaths this year? In the last 10 years? Since records began? Without some context they can be dismissed. Likewise the lack of a source weakens the strength of the argument and makes it appear the numbers were pulled out of thin air. A little line at the bottom saying "Statistic taken from XXYY" gives the entire thing more weight.
"The only businesses guns are good for are funeral homes and grave diggers" isn't a bad line but it's flawed both in general and the execution here. The general flaw is trite but powerful; surely guns are also good for gun shops? I think almost everyone would accept they are and once they've accepted that they've accepted that the central message of the poster is wrong. Once they've accepted that the central message is wrong it's easy to dismiss the rest even if they really shouldn't. The issue with execution here is that while one part of that tag line clearly corresponds with the map (funeral homes and grace diggers corresponds to gun deaths) the "the only businesses" part doesn't; there's nothing about other businesses in the map of explanatory text which means it loses power and seems disjointed. Either find some statistics that seem to show that looser gun control means lower revenue for other businesses (it's a propaganda poster so you don't need to worry about the whole correlation doesn't equal causation thing) or change the line. Mentioning gun suicides is a bit of a red herring as well; the obvious counter is to say that people can kill themselves without guns and while you in turn could argue that easy access to guns make it a lot easier to commit suicide etc etc you've now been drawn into a debate and debate is the mortal enemy of propaganda.
The entire thing, both in presentation and in what's included, comes across as just being a bit messy, as if you found a bunch of statistics and threw them onto a page without much care for how they looked or the impact they could have. Just a few relatively simple changes to both would give it a lot more impact.