The Republic was killed in 1861. It was driven further into the ground in 1913 with the passage of the Federal Reserve Act and the shady shoving through of the 16th amendment. It was stomped on yet again in 1933 with the passage of House Joint Resolution 192. Then there was Nixon ending Bretton Woods and dishonoring the obligation to redeem the dollar for gold in 1971. The PATRIOT (sic) Act was another nail in the coffin as well as the Military Commissions Act. Also the bailouts of 2008. We live under a system of government where the president can, without any due process (charges, arrest, trial by jury), execute a citizen. This can hardly be considered a republic.
There have now been multiple generations of Americans taught in the youth propaganda camps (government schools) that government is god. The vast majority of Americans have been so hopelessly indoctrinated with statism that they have absolutely no concept of the rule of law. They now believe in "might makes right" because the god they worship (government) rules them at gunpoint, so the logical assumption is that this is a good thing The vast majority of Americans, regardless of which side of the false left/right paradigm they identify with (R or D), are now social democrats. They have no problem with other people's rights being violated as long as it does not affect them or those they care about. They don't mind government holding up strangers at gunpoint if it is to their benefit. But they will squeal like hell when the tyranny they have endorsed comes down on them. They have no understanding that when one person's rights are violated, every person's rights are violated.