In case you hadn't heard, Bernie Sanders is running for president again. The independent senator from Vermont and 2016 wrench in the Democratic Party machine has been hitting the 2020 campaign trail hard, trying to hold a solid position in second place across several dozen polls, with Joe Biden out ahead of him and Elizabeth Warren and Kamala Harris hot on his heels. Sanders tells Teen Vogue his campaign intends to win the Democratic primary and defeat “the most dangerous president in American history.”

The democratic socialist is pleased to see that many of his policy views deemed too “radical” in his 2016 primary run are becoming debate-stage topics. Over the last four years, he’s watched ideas he championed then (Medicare for All, tuition-free college, and more) become mainstream liberal politics even as he remains a leader on these issues and a crusader against Wall Street and the corporate health care system.

It is strange to think that Sanders, a man who has been in Congress as long as I’ve been alive, represents such vocal resistance to the very system he’s so long been a part of. But the presidential candidate’s call for a “working-class revolution” (specifically, a political revolution) feels like more than just rhetoric when proposals like eliminating all student loan debt are on the table.

Listening to Sanders, you get the sense that he feels a duty to save this country and this planet and that being a part of the system is a necessary condition for that moral obligation.

Sanders visited the Teen Vogue offices this week, where he discussed some of his 2020 competitors, how to combat an impending sense of nihilism about our shared future, and what’s so special about this moment’s political superstar, Alexandria Ocasio-Cortez.

Teen Vogue: Let’s start with the issue of climate. You were a part of the congressional move to propose declaring a climate emergency. Could you tell us about the thinking behind that?

Bernie Sanders: Here is the truth: We face an unprecedented moment in human history. I’m not talking about modern history; I’m talking about human history. The scientific community has told us that we face an existential crisis. We’re seeing the warmest years on record. The scientific community is telling us that if we do not boldly and aggressively transform our energy system away from fossil fuel to energy efficiency and sustainable energy, we’re going to see irreparable damage to this planet.

We are already seeing massive damage. It will get worse. If we do not act, then the planet we’ll be leaving to our children and future generations will be increasingly unhealthy and uninhabitable.

What we did the other day working with Representative Earl Blumenauer and Representative Alexandria Ocasio-Cortez is introduce a resolution which says that climate is a national emergency, which, to me, is a no brainer. If we’re talking about saving the planet, I think, "Duh. Yeah. It is a national emergency." As president, what I will do is not only help transform the energy system of this country away from fossil fuels, but bring the entire planet together.

There is no issue I can think of more important. It is a moral imperative to do the right thing.

What I want to say also is we can come up with all the plans we want — and I can give you 20 plans. Doesn’t mean anything unless we have the courage to do what? Take on the fossil fuel industry, and they are very powerful. They’re making billions while they’re destroying the planet.