And independent Senator Bernie Sanders of Vermont has announced his bid for the Democratic presidential nomination. Launching his campaign, Sanders said the nation’s “immoral” economic system favoring the wealthy cannot continue.

Sen. Bernie Sanders: “All over this country, I’ve been talking to people, and they say, 'How does it happen? I'm producing more, but I’m working longer hours for low wages. My kid can’t afford to go to college. I’m having a hard time affording healthcare.’ How does that happen, while at exactly the same time 99 percent of all new income generated in this country is going to the top 1 percent? How does it happen that the top 1 percent owns almost as much wealth as the bottom 90 percent? And my conclusion is that that type of economics is not only immoral, it’s not only wrong, it is unsustainable. It can’t continue.”

Sanders had floated his potential candidacy for months, repeatedly saying he would only run if he sensed there was sufficient grassroots support. He will campaign as a self-described “independent Democrat,” because running as a third-party candidate would have been too difficult. He is the first official challenger to Democratic frontrunner Hillary Clinton so far. In a tweet on Thursday, Sanders said he looks forward to debating Clinton on “the big issues: income inequality, climate change, and getting big money out of politics.”