“When politicians insult Muslims, when a mosque is vandalized, or a kid bullied, that doesn’t make us safer. That’s not telling it like it is. It’s just wrong. It diminishes us in the eyes of the world. It makes it harder to achieve our goals. And it betrays who we are as a country… What I’m asking for is hard. It’s easier to be cynical; to accept that change isn’t possible, and politics is hopeless, and to believe that our voices and actions don’t matter. But if we give up now, then we forsake a better future. Those with money and power will gain greater control over the decisions that could send a young soldier to war, or allow another economic disaster, or roll back the equal rights and voting rights that generations of Americans have fought, even died, to secure. As frustration grows, there will be voices urging us to fall back into tribes, to scapegoat fellow citizens who don’t look like us, or pray like us, or vote like we do, or share the same background. We can’t afford to go down that path. It won’t deliver the economy we want, or the security we want, but most of all, it contradicts everything that makes us the envy of the world.”

Principles and Priorities : Programme for Government (September 5, 2007)

As quoted in "After Ottawa Shootings, Shep Smith Urges Public Not To 'Give In' To Panic" https://web.archive.org/web/20141028004609/http://www.huffingtonpost.com/2014/10/23/shepard-smith-ottawa-shooting_n_6035208.html (October 23, 2014), by Avery Stone, The Huffington Post, The Huffington Post, Inc.
2010s

“When Will We Learn?”, posted one day after 9/11, Antiwar.com, (Sept. 12, 2001).
2000s

2010s, Farewell Speech (2017)
Context: When you encounter obstacles — because I guarantee you, you will, and many of you already have — when you are struggling and you start thinking about giving up, I want you to remember something that my husband and I have talked about since we first started this journey nearly a decade ago, something that has carried us through every moment in this White House and every moment of our lives, and that is the power of hope — the belief that something better is always possible if you're willing to work for it and fight for it.
It is our fundamental belief in the power of hope that has allowed us to rise above the voices of doubt and division, of anger and fear that we have faced in our own lives and in the life of this country. Our hope that if we work hard enough and believe in ourselves, then we can be whatever we dream, regardless of the limitations that others may place on us. The hope that when people see us for who we truly are, maybe, just maybe they, too, will be inspired to rise to their best possible selves.

2015, State of the Union Address (January 2015)
Context: When we make rash decisions, reacting to the headlines instead of using our heads; when the first response to a challenge is to send in our military -- then we risk getting drawn into unnecessary conflicts, and neglect the broader strategy we need for a safer, more prosperous world. That’s what our enemies want us to do. I believe in a smarter kind of American leadership. We lead best when we combine military power with strong diplomacy; when we leverage our power with coalition building; when we don’t let our fears blind us to the opportunities that this new century presents. That’s exactly what we’re doing right now. And around the globe, it is making a difference. [... ] That’s how America leads -- not with bluster, but with persistent, steady resolve.

We nominated Jeremy Corbyn for the leadership. Now we regret it (6 May 2016)

2013, Brandenburg Gate Speech (June 2013)

Source: Sons of Destiny

Epilogue - Cannon Beach
The Lonely Dead (2004)