Superficially, background checks sound like a good thing.
They are- currently in the United States if you wish to purchase a gun, you must fill out a 4473. This form screens the applicant to see if they are ineligible for a firearm. 4473's are easily falsified by the customer. Threats of perjury have not stopped people from lying on their 4473s. The gun store is required to keep the record of the sale for approximately 10 years; some keep them for as long as they are in business.
By federal law, the government (which doesn't listen anyways) cannot keep a national registry of firearms. 4473s are for the sole purpose of aiding investigators on a paper trail if any crime is committed with the weapon. If you do make a private sale of a firearm, making sure to take the person's information (and even questioning if they are prohibited) this is why you create a bill of sale with whom you made the transaction with. You filled out the 4473; the cops are gonna come after you. You have the bill of sale, and they move to go after the guy you sold the firearm to. Many uneducated buyers think 4473s are gun registration. They are not. In most of the free United States, there is no such thing as gun registration. Registration, in many cases, from Nazi Germany to England to Australia- has always lead to confiscation when "registration didn't work, so now we need to confiscate".
In addition to the 4473, the applicant must pass a background check. This is true if the buyer is at a gun show or if inside a gun store. Once the background check clears, and the 4473 is filled out correctly, typically one can purchase the firearm right then and there (it is ultimately the shop's discretion).
But what about neighbors who want to loan, sell or buy a gun from one another, or the father who wants to pass on an heirloom to his son? This is what the anti's are now focusing on.
Universal Background Checks are a background check expanded to every transfer and sale of a weapon. If you move the weapon out of state, you would need a background check. Want to loan it to your neighbor? background check. Sell it to your son? background check.
Do UBCs violate the 2nd Amendment? let's take a look at what the 2nd has to say:
"A militia, being necessary to the security of a free state; the right of the people to keep and bear arms shall not be infringed".
Without analyzing the entire amendment, the Constitution grants a US citizen the right to:
a) keep a firearm (firearm, not "gun" or "explosive device").
b) bear a firearm (bear a firearm in self-defense of person or liberty in public or private
for the purposes of:
d) overthrowing a tyrannical government
e) other lawful purposes
The word infringed means to violate, undermine or restrict. To keep a firearm is to own a firearm. In the case of the 2nd Amendment, in a manner that does not infringe upon that right. Universal Background Checks further restrict movement of lawfully owned firearms and aim to punish the law abiding citizen.
If enacted, will UBCs stop the criminal? no. Why? for two reasons:
1) CRIMINALS DO NOT OBEY THE LAW.
2) Criminals will not hand off their "pieces" for the commission of a crime at their nearest FFL dealer.
So what alterior consequences exist for UBCs? The gov't has been thinking about creating a database to monitor all of these background checks. Because every movement of a firearm would be monitored and recorded, this is in fact back door gun registration, another impediment to your right to keep and bear arms.
UBCs will not make us safer. They are "feed good" measures that, as Coloin Noir once penned "are like putting band-aids over bullet holes".
The right thing to do is to begin prosecuting criminals/felons with guns (the gov't argues it does not have the capacity to do so) and increasing their sentencing time as a penalty. But more to the point, poverty, disadvantage and poor schooling need to be immediately addressed to minimize the impact on crime committed by gang activity and the mentally ill.