Spoiler The NCR was originally only Shady Sands than other towns decided to join by their own free will. Limited trade was opened up and ideas were exchanged. As a result, a national identity took shape. This was all during Aredesh's time in office. Then the idiot decided to search for Vault 13 and got himself killed. After that, Tandi took over. While Tandi had done good for the NCR (minus the whole Vault City fiasco), they were doom to fall from grace since it was Tandi that kept the NCR "democratic" but it wasn't exactly "democratic" per se. The NCR is a republic. The common citizens vote for other people to speak for themselves. But that's besides the point. After Tandi dies, the NCR began to change its course of direction. I won't go into details but the Mojave Campaign is a great example that the NCR is NOT "democratic".
They came and saw Hoover Dam.
They now want Hoover Dam.
Why?
Because it can produce electricity for their citizens.
But there is a problem.
There are already people living in the Mojave. The Mojave isn't part of the NCR. That's why in the NCR it is known as the Mojave Campaign. If you speak with countless NPC's many will show their distaste for the NCR.
Goodsprings is a great example. The Followers of the Apocalypse (they were basically "kicked" out because the people in power consider them "anarchists" despite the followers being a peaceful folks) and Novac.
Do you remember the quest where you have to redirect the electric power from Helios One? Where did the NCR wanted it sent to? Yeah, thought so.
Now look at the situation between Colonel Moore. She basically asks you to massacre an entire bunker of hiding BOS members. She also wanted to use violence to solve the Freeside's problem (Caused by Pacer). Plus, according to Cass, the NCR is rounding up Tribals and pretty much forcing them to assimilate because they are considered backwards. I wonder if the Tribals would be happy about that....
Oh, we can't forget about Primm and their escaped convicts problem. Did the NCR raised a finger to help them. Nope.
And two words: the Divide.
'nuff said.
In the end, yes, the NCR is a bit more "civilized" compared to the Legion but I wouldn't go as far and call them "democratic".
They really only care about themselves.
Check the definition of democratic. As I understand, a democracy is where common people vote for other people to represent them, which is kind of what you've described the government of the NCR as (that's certainly how the democracy in my country works). Does the NCR have a corrupt bureaucracy? Undoubtedly. What country doesn't have a corrupt bureaucracy? Occupying foreign territory for resources might not be the nicest thing to do, and the NCR has certainly done some morally dubious things in the process, but does that change the fact that they are a democracy? Let’s think of a well known real life country that has a corrupt bureaucracy and occupies other nations for the sake of resources that generate electricity and doing all sorts of morally dubious things in the process. Are they a democracy? I'd say yes, personally.
(In other words, I'm saying that the logic of using the Mojave campaign to justify the NCR not being democratic is like saying the Iraq war makes the USA undemocratic. The occupation of the West Bank is probably an even better example; by this logic Israel clearly isn't democratic, except it is, and generally quite a bit more than its neighbours...which...wait...isn't that a bit like the NCR's situation. Please don't read into that as me commentating on the real life conflict, either.)
Also, you highlight Colonel Moore as an example of why the NCR is bad. What if you'd looked at Chief Hanlon instead or even Ambassador Crocker? That'd give the NCR a completely different appearance, wouldn't it? And for that matter, the NCR officer at Primm wants very much to help the town, however, he is faced with a shortage of supplies that prevent him from doing so.
Look, the NCR has problems with its leadership. Its causing pain both to the NCR and the people on its fringes. But at the same time, the NCR, based on what we know, has brought law, order and high living standards to hundreds of thousands of people. Is 'killing' this society, which is blatantly reminiscent of our society, justified? Or is it better just to remove the leadership which is causing the problems. I'd choose the latter, personally.