It might be worth expanding on that last post.
You make the assumption more gun laws would reduce gun deaths. I disagree with this, but admit it is difficult to empirically test (More on this later). There are problems in the possible observational studies that use different countries, look between different regions of the US, or within the same region at different time points. I find some of the comparisons more compelling than others, but they also tend to support my general views so I am likely being effected at least in part by my own bias. Never the less, because you are assuming this premise without a constant theory that deals with the counter examples, you introduce flaws into your arguments.
You also falsely assume people not agreeing with your proposed changes are pro-current laws. People may be in support of different laws, the removal of current laws, or changes to those laws. Gun laws are changing all the time, they are just generally going
in the direction you do not support. Moreover, murder and violent crime rates have been decreasing over the last 20 years which coincided with the massive liberalization of firearms laws in the US. This is the opposite of what your logic would predict. Of course there are other factors besides gun laws in the murder rate, but that only points towards the absurdity of accusing those who don't agree with your proposed laws as being against the goal. I am quite sure I have heard many a republican opine in the last week about the need for other solutions they consider to be more appropriate to the problem.
You also draw a false equivalence that the republican position is an endorsement of gun deaths. This is no different than someone arguing that opposing a 5mph speed limit and stopping for 30 seconds at every stop light is endorsing 50,000 car deaths per year. While such laws would reduce the number of people killed by cars, people can oppose those laws for reasons totally unrelated to the number of car related fatalities.
While I support your desire to reduce these horrible incidents, you should understand that making fallacious arguments and accusing half the people of being pro-child murder is not going to sway very many people to your side, you lose out on both the logical and the emotional reactions that way.