In the US (which I'm assuming you're referring to, since the meme mentions the GOP), There is absolutely not a background check performed for every firearm purchase. That's one of many restrictions people reasonably want placed on guns. Only 17 states have a universal requirement for gun sales. The federal law "requiring" background checks only applies to federally licensed sales. Private sales, gun shows, etc. allow for sale of guns with no background check, and often bypass age restrictions as well.