Not sure the Republican party is very beholden to republican values either, instead of plutocratic ones on the whole, and theocratic ones for a minority, of its members. Just saying. (For that matter in the UK, the Labour party seems to have forgotten those who labour, and the Conservatives are hardly that, so I’d not say it’s just a US problem).
Whether we call what we have right now in the West, democracy or another word, is a pretty bad idea, quite honestly. It’s what we seem to be heading towards, as ever more emphasis is placed on instant reaction from e.g. twitter, rather than actual reasoned debate and nuanced thinking. What the composers of the U.S. Constitution, or custom in the UK, assumed, was not democracy, and ‘letting the people speak’ about every issue. Our representatives in our legislatures are meant to be the ones considering how things work. (In the case of the US, particularly in the upper house of Congress, etc). But that’s no longer what happens. In an age when everyone can yell all across the country via the internet, people seem not to be patient with reasoned debate any more.
I’m not fearful about liberal democracy, but I’m fearful of an unminded, pure democracy where the only thing that counts is how many people support your point of view, and which group of people shout the loudest.
The historian Polybius wrote about this about 150 years before Christ was even born. I think in the modern world, as someone has already written above, we can probably lay a lot of the blame on the internet - or more precisely on our inability to control ourselves when given free rein to not-indulge our critical faculties. What we’ve ended up with, or are heading towards, isn’t democracy, pure or representative, but ochlocracy. The rule of the mob. And it’s even easier to go from that, to tyranny.
This isn’t a failure or even really a fault of liberal democracy. It’s a failing by all of us who live in it not to do our damnedest to rise above our baser tendencies and actually think and value good things. I don’t mean by making sure we obey all the Commandments, precepts of the Church, and try to get our governments to (as far as possible in a secular state) follow them too - but by actual thoughtful participation in our democratic processes. There is no such thing as not having enough time to remain at least a little informed of current events, finding out facts for oneself instead of being spoonfed subjective opinion from the left or the right-wing bits of the media.
In an age when it seems we can’t always trust journalists, any more than politicians or business leaders, it is beholden on us, the people, do at least do the job of journalists ourselves: holding everyone else to account. We cannot afford to be narrowminded, or ill-informed, about anything.
Until we have forced a change to restore accountability within all our institutions, we have to do all this ourselves. It’s the only way to restore liberal democracy to what it should be, or at least to point it again in the right direction.