As he outlined his progressive agenda on Monday, Bernie Sanders said the upcoming Democratic National Convention in Philadelphia could get "messy," adding: "Democracy is not always nice and quiet and gentle."

Sanders spoke with the Associated Press as he announced his picks for the Democratic National Committee's platform drafting panel—which included a group of renowned progressive activists, scholars, and lawmakers such as Dr. Cornel West, Rep. Keith Ellison, and Native American activist Deborah Parker—and called on the party to allow newcomers a platform at the convention.

The Vermont senator said:

We are bringing in a lot of new people into the political process, people who have never gone to a convention before, and they hope very much that their voices will be heard. The leadership of the Democratic Party has a very fundamental choice to make. And that choice is do we open the doors to many, many million of people—often working-class people, people who are working maybe two or three jobs to make ends meet—to young people who have never perhaps voted in their lives? Do we say, 'hey, come on in, we're delighted to have you, we're excited to have you, this is great for the Democratic party.'

Or do we say, 'hey, you know, you're not really one of us. We're too busy going to fancy fundraisers at $50,000 a plate, and you're really not what this party wants.' That's the choice.

"I think if they make the right choice and open the doors to working-class people and young people and create the kind of dynamism that the Democratic Party needs, it's going to be messy," Sanders continued. "Democracy is not always nice and quiet and gentle but that is where the Democratic Party should go."

"Democracy is messy," he continued. "Every day my life is messy. But if you want to be quiet and orderly and allow... things to proceed without vigorous debate, that is not what democracy is about."

The interview comes just ahead of the California primary on June 7, where 475 pledged delegates are at stake.

"What happens if I win a major victory in California? Will people say, 'Oh, we're really enthusiastic about Hillary Clinton despite the fact that Bernie Sanders has now won whatever it may be, 25 states, half the states?'" he said.

In that case, he said, superdelegates "may rethink that."

"This is why you want the process to play out."

Watch Sanders' interview below: