One decline in democracy: do you belong to any organization where the members regularly vote, make binding decisions, and occasionally fire the leader? A co-op? A union? A club? A homeowner's association? Anything? Most non-profits and voluntary organizations used to be organized that way, but in the US today, they tend to have self-perpetuating boards, ones which choose their successors.
This is a problem for democracy, because Americans don't regularly do democracy any more. It takes practice. You need to see the process work. If people are not familiar with the process, it won't get used.
Democracy is a consensus-forcing process. There's argument, then a vote. Then a decision, which is carried out. The expectation, and this is a tough one, is that after a decision is made, the opposition mostly accepts it, whether they like it or not. That's tough. Countries currently struggling hard with that include the US, France, and Israel.
If voting can't force a decision and action, democracy stalls. This leads for calls for a "strong leader" and some form of autocracy. Countries which failed at democratic consensus and ended up as authoritarian states in recent years include post-USSR Russia, and Iraq.
Then you get a coup or conquest, sometimes you get a revolution, and once in a while, a stable democracy emerges. You have to have people who know how to do democracy to make that work.