U.S. President Barack Obama smiles while the audience sings "Happy Birthday" to him before he speaks about home ownership at Desert Vista High School in Phoenix, Arizona Aug. 6, 2013. Reuters/Larry Downing

U.S. President Barack Obama turns 55 Thursday. He's nearing the end of tenure as president as Democratic nominee Hillary Clinton and Republican nominee Donald Trump are locked in a contentious battle to take lay claim to the Oval Office.

Obama's an increasingly popular president, his approval rating hovering at about 50 percent, up from the 40s last year. Listed below are 17 quotes, and some video clips, to honor the president as he enters his mid-50s. Quotes collected from CNN, Brainy Quote, amNY, Business Insider, and the White House's website.

1. "Democracy isn't a spectator sport."

2. "In my final year, my approval ratings keep going up. The last time I was this high, I was trying to decide on my major."

3. "The thing that got me through that moment, and any other time that I've felt stuck, is to remind myself that it's about the work."

4. "Change will not come if we wait for some other person or some other time. We are the ones we've been waiting for. We are the change that we seek."

5. "The future rewards those who press on. I don't have time to feel sorry for myself. I don't have time to complain. I'm going to press on."

6. "There's one area where Donald's experience could be invaluable, and that's closing Guantanamo. Because Trump knows a thing or two about running waterfront properties into the ground."

7. "If you're walking down the right path and you're willing to keep walking, eventually you'll make progress."

8. "Now, as a nation, we don’t promise equal outcomes, but we were founded on the idea everybody should have an equal opportunity to succeed. No matter who you are, what you look like, where you come from, you can make it. That’s an essential promise of America. Where you start should not determine where you end up."

9. "We worship an awesome God in the Blue States, and we don't like federal agents poking around our libraries in the Red States. We coach Little League in the Blue States and have gay friends in the Red States."

10. "In the end, that's what this election is about. Do we participate in a politics of cynicism or a politics of hope?"

11. "It was not a religion that attacked us that September day. It was al-Qaeda. We will not sacrifice the liberties we cherish or hunker down behind walls of suspicion and mistrust."

12. "If the people cannot trust their government to do the job for which it exists - to protect them and to promote their common welfare - all else is lost."

13. "My fellow Americans, we are and always will be a nation of immigrants. We were strangers once, too."