On background checks and the NICS database:
We already have them in place and they don't even prosecute when criminals try to get around it.
That is because the NICS database is so riddled with inaccuracies that they cant tell who is prohibited and who isn't. Starting prosecutions based on an unreliable database is a non-starter. Hundreds and thousands of folks would go to jail, post bond (or sit in jail), go to court, be exonerated, countersue, and end up costing the Feds a whole lot of money and a whole lot of very, very bad PR. The whole "background check" would be dead in the water... forever. Remember, if only a few % of records are incorrect, that represents a LOT of innocent people.
They would rather quote how they "kept 10,000 guns from criminals" than admit the database stinks, and that they falsely rejected a pile of legitimate purchases.
Further, an entry in a NICS database is not PROOF of ineligibility. It is merely proof that someone put a record in that database with my (your) name on it. To rely on NICS, the Feds would have to research every entry back to its source. Sometimes, that source may no longer exist!
For proof of all that I have asserted, lets look at ME:
I was falsely denied. NICS had me listed as a felon due to a clerical error when a small town was digitizing their records. Those physical records no longer exist! I spent a year clearing my record. When anyone actually looked at it, it was CLEAR that a misdemeanor and $100 fine from a youthful indiscretion was incorrectly transcribed into the state/federal databases as a FELONY. Sure, they could (and did) deny my purchase of a firearm. But if they had tried to PROSECUTE me for it, nothing but badness for the State/Feds (and their much vaunted database) could have come from it. Yes, it would have been bad for me to start, but it would quickly be shown to be a comedy of governmental errors. That is not the thing you want to put on display to the voting population. As a side note, I took on clearing my name. I did it because it cost me nothing. I got lucky that a clerk in the police department where the mistake was made (20 years ago) took it upon herself to fix this error. In doing so, she got the police chief and a judge to sign off on the change to my state record, which fixed the Federal/NICS record. If I had needed an lawyer to get this done, I might not have had the financial resources to do so. So just because someone in the NICS system was denied and did not appeal STILL does not imply "guilt". It may very well imply lack of financial resources.
What this means is that the stuff in the NICS database is not PROOF of ineligibility. If you arrest someone for something in NICS, his/her guilt is NOT BEYOND A REASONABLE DOUBT. There is an appeal process! With an appeal process, they have essentially admitted that the NICS database contains errors. And knowing that, every single one of those denials would have to be researched in-depth before bringing charges against someone for a denial. Worse than that, every one of those denials would have to be researched in depth before even making an arrest.
With such obvious flaws, why do politicians keep pushing NICS background checks? I can only think of one reason: backdoor registration.