Yes, there are dangers to the Republic, and yes, I would agree with you that they are of a socialist or "social democratic" nature primarily, but the underlying quotation is just bullshit. We have had a democracy for over 200 years, and in all that time voters have been aware that they may vote themselves gifts out of the public treasury. That by itself does not determine the vitality of a democracy, and anyone who thinks that is against free societies and advocating dictatorships of one sort or another. While there is a trend that more and more people are expecting something from the government, it's not a natural or inevitable consequence of the power to do so, and its causes are probably more complex than a simple response could delve into. It does, thankfully, have simple solutions (like Welfare Reform showed us). We just need to convince a simple majority that they are good and fair solutions. I think that can be done. It might not be easy, but it can be done.

More disturbingly, however, the quotes in the original post are defeatist quotes. They imply an inexorable decline, one that no amount of civic virtue, patriotism, American ingenuity or determinism can overcome. That is in and of itself bullshit. Democracy is a feeble flame, yes, but it is one that each generation can find the strength to preserve. If it fails, it fails because of our failures, not because of a preordained decline.

So no, it's not true.