WASHINGTON (Reuters) - U.S. President Joe Biden on Friday will tell the Munich Security Conference that “democracy doesn’t happen by accident” and that democracy must prevail over autocracy. “We have to defend it. Strengthen it. Renew it. We have to prove that our model isn’t a relic of our history. It’s the single best way to realize the promise of our future. And if we work together with our democratic partners, with strength and confidence, I know that we will meet every challenge and outpace every challenger,” Biden will say, according to excerpts of his speech released by the White House.