You know, I don't often discuss my political views because I'm a moderate with pragmatic leanings, and chances are, no matter color of the political spectrum that you inhabit, I probably agree with you on around 50% of your views. My mom is a Tea Party member, and she and I have lots we agree on. I have friends who are tree-huggin' socialist Occupy types, and we have lots we agree on.
However, background checks for gun purchases are a pragmatic step, and the time has come to institute them.
If you haven't committed a felony or don't have a violent mental illness diagnosis, why are you worried?
The "Slippery Slope" argument is a fallacy. The Second Amendment protects the rights of law-abiding citizens to have and hold guns. Convicted felons and mentally ill people who are a danger to others are stripped of their constitutional rights, which includes the rights to liberty, representation through voting, and to bear arms.
We have locked convicted felons in prisons and not allowed them to vote for centuries, but no one has taken those rights away from law-abiding citizens. Denying violent criminals and violent mentally ill people access to firearms will not impinge on law-abiding citizens' rights.
While any one criminal or mentally ill person may still be able to access a firearm, reducing the percentage of the violent population who can access firearms will reduce the number of crimes.