“We have to include a wider array of institutions—to distinguish democracy from authoritarian governments, and even there we need a scale to do so. But it means not just elections, indeed free and fair elections; I think it’s come in the twentieth century to mean a universal electorate, male and female, moving the age down a bit, that’s now just standard. Political parties and political competition and free and fair elections, and something that I’ve tried to add on, without, I suppose, a great deal of success in the real world or elsewhere: the ultimate popular control over the agenda.”

"Public Papers of the Presidents of the United States: George W. Bush" http://books.google.co.kr/books?id=1mEa-o1LGa8C, p.617
2000s, 2006

2015, Remarks to the People of Africa (July 2015)

"The Situation Is Not Easy" by Lally Weymouth in Newsweek (26 April 2010) http://www.newsweek.com/id/236580/output/print

1860s, On Democratic Government (1864)
Context: If the loyal people united were put to the utmost of their strength by the rebellion, must they not fail when divided and partially paralyzed by a political war among themselves? But the election was a necessity. We cannot have free government without elections; and if the election could force us to forego or postpone a national election, it might fairly claim to have already conquered and ruined us. The strife of the election is but human nature practically applied to the facts of the case. What has occurred in this case must ever recur in similar cases. Human nature will not change. In any future great national trial, compared with the men of this, we will have as weak and as strong, as silly and as wise, as bad and as good. Let us, therefore, study the incidents of this as philosophy to learn wisdom from, and none of them as wrongs to be revenged.

May 30, 1999. Quoted in "Armenian ex-communist leader Demirchyan confident of fair elections" - BBC Archive.

2016, DNC Address (July 2016)
Context: I think it's fair to say, this is not your typical election. It’s not just a choice between parties or policies; the usual debates between left and right. This is a more fundamental choice — about who we are as a people, and whether we stay true to this great American experiment in self-government.
Look, we Democrats have always had plenty of differences with the Republican Party, and there’s nothing wrong with that. It’s precisely this contest of idea that pushes our country forward. But what we heard in Cleveland last week wasn’t particularly Republican — and it sure wasn’t conservative. What we heard was a deeply pessimistic vision of a country where we turn against each other, and turn away from the rest of the world. There were no serious solutions to pressing problems — just the fanning of resentment, and blame, and anger, and hate.
And that is not the America I know. The America I know is full of courage, and optimism, and ingenuity. The America I know is decent and generous.

2014, 25th Anniversary of Polish Freedom Day Speech (June 2014)

2014, Queensland University Address (November 2014)
Context: America supports free and fair elections, because citizens must be free to choose their own leaders -- as in Thailand where we are urging a quick return to inclusive, civilian rule. We support freedom of assembly, and freedom of speech, and freedom of the press, a free and open Internet, strong civil societies, because the voices of the people must be heard and leaders must be held accountable -- even though it’s uncomfortable sometimes. [... ] We support strong institutions and independent judiciaries and open government, because the rule of force must give way to the rule of law. And in that same fashion, the United States will continue to stand up for the inherent dignity of every human being. Now, dignity begins with the most basic of needs -- a life free of hunger and disease and want.

http://www.gothamgazette.com/searchlight/2004.state.of.city.bloomberg.shtml
Why He Was Elected Mayor