Presidential elections always turn on personalities, they turn on how campaigns are run, they turn on natural desires for change.

If we aren't willing to pay a price for our values, then we should ask ourselves whether we truly believe in them at all.

The Iranians may simply try to run out the clock.

For all the noise and anger that too often surrounds the immigration debate, America has nothing to fear from today's immigrants. They have come here for the same reason that families have always come here-for the hope that in America, they could build a better life for themselves and their families. Like the waves of immigrants that came before them and the Hispanic Americans whose families have been here for generations, the recent arrival of Latino immigrants will only enrich our country.

My relationship with Silicon Valley and the tech community historically has been really good. Many of these folks are my friends.

We need scientists to design new fuels. We need farmers to help grow them. We need engineers to invent new technologies. We need entrepreneurs to sell those technologies. We need workers to operate assembly lines that hum with high-tech, zero-carbon components. We need builders to hammer into place the foundations for a clean energy age. We need diplomats and businessmen and women, and Peace Corps volunteers to help developing nations skip past the dirty phase of development and transition to sustainable sources of energy. In other words, we need you.

I've called on Congress to repeal the so-called Defense of Marriage Act to help end discrimination to help end discrimination against same-sex couples in this country. Now, I want to add we have a duty to uphold existing law, but I believe we must do so in a way that does not exacerbate old divides. And fulfilling this duty in upholding the law in no way lessens my commitment to reversing this law. I've made that clear.