Well put, 'Two Kids' Dad', I couldn't have said it better myself.
Law enforcement simply cannot logistically pull off a massive national gun confiscation effort. They simply do not have the numbers, even with National Guard and Military reinforcements, to pull it off in a short period of time - it would take months and months to go door to door, especially in states where there is NO gun registration!
Unless the dictatorial authorities shut down all internet and telephone/cellular communications, word would circulate nationally very quickly, even if the lame stream media remained silent, after the first 24 - 48 hours of this gun confiscation effort amongst Patriots and likely by day three, you would see massive organized resistance to any future confiscation efforts most everywhere.
Like some posters have also pointed out, the families of the cops live amongst the public, as well as the families of that states National Guard members and would likely be targeted by organized resistance groups. If this massive gun confiscation effort was ever to be undertaken, these now organized Patriots could take the families of these cops and National Guardsmen into a sort of 'protective custody' to help ensure 'good behavior' by the cops or National Guardsmen towards the Patriots to the point where they refuse orders to confiscate any weapons from any Citizens, provide valuable intelligence to Patriot groups relative to future movements/plans of government gun confiscation efforts or even encouraging the cops/National Guardsmen to desert their jobs/posts in order to ensure their relatives in Patriot custody are not harmed.
Of course, if there is seriously any nationwide effort to confiscate guns under consideration, it wouldn't suprise me to see plans where all the families of cops, National Guardsmen and Active Duty Military moved into safe, onbase, guarded dependent housing just prior to the commencement of any effort at massive nationwide gun confiscation.