Entrepreneur and 2020 presidential candidate Andrew Yang (D) is calling out Sen. Bernie Sanders (I-VT) for “backward-looking” solutions that are trying to “resuscitate” last century’s economy while raising concerns about Sanders’—and former Vice President Joe Biden’s—“advanced age.”

In the latest episode of Preet Bharara’s “Stay Tuned” podcast, Yang, who will be on the stage for the first two debates and is better positioned than most Democrats to make the stage in subsequent debates, previewed potential lines of attacks that he could use against the party’s frontrunners. He said it is better for Democrats to take the gloves off in the primary season and put everything out in the open to better prepare the nominee for the general election.

Yang, who is running on giving a “freedom dividend” of $1,000 a month to every adult citizen, said that Sanders is sincere about wanting to fix the economy and revealed that he liked and supported him in 2016. But he said Sanders’ solutions to today’s economic problems are “very backward-looking” are “trying to resuscitate an economy that existed at some point in the 20th century, and a lot of that is going to be very, very hard to actually materialize in real life.”

He also said Democrats need to ask about the “advanced age” of Sanders and Biden because every voter is thinking about it. Yang said that on the campaign trail, if someone has an issue with either Sanders or Biden, age is one of the first things that always comes up when he is talking to Democrats.

Yang believes Democrats need to have a “real conversation” about whether having a presidential candidate whose “advanced age is actually an issue is ideal for the party or the country.”

This is not the first time Yang has gone after Sanders.

Yang previously ripped Sanders as “close-minded” for dismissing his “freedom dividend” proposal to give every American adult $1,000 a month. His campaign also called out Sanders for blatantly lying by omission when Sanders, perhaps revealing that he sees Yang as a threat, sent out a graphic showing that he topped the 2020 field last quarter when it came to small-dollar donations while conspicuously not including Yang, who came in second.

In hindsight, Sanders’ omission was a sign that the Sanders campaign perhaps realized that Sanders did not have a lock on younger and more progressive primary voters. A recent Quinnipiac poll, for instance, actually found that “very liberal” Democrats nationally backed Sen. Elizabeth Warren (D-MA) and not sanders.

Yang mentioned then that he was “surprised” that Sanders, perhaps trying to seem less “revolutionary” now that he is one of the frontrunners to take on President Donald Trump in 2020, is now against universal basic income.

“Bernie’s answer when asked about Universal Basic Income recently seemed closed-minded and a departure from his previous position on it,” Yang said. “Of course Basic Income is a part of the solution. I think he knows that.”

Yang linked to a YouTube clip of Sanders rejecting his “freedom dividend” proposal by uttering gibberish about infrastructure, daycare, training social workers and doctors, and transforming the country’s energy system to guarantee a job to anyone who is willing to work.

Yang’s campaign also noticed that Sanders strangely omitted Yang in a campaign graphic that touted that 84 percent of Sanders’s contributions in the last fundraising quarters came from people who donated $200 or less. Yang, who often says his supporters are even cheaper than Sanders’s, received 81% of his contributions from those who donated $200 or less, which placed him second. Mainstream media outlets like CNN even prominently featured yang in their graphics, and Yang’s campaign manager quickly “fixed” the graphic that Sanders posted on his social media accounts.

“Bernie Sanders knows better than anyone what it is like to be excluded by establishment politicians,” Yang said. “It’s too bad that he is not more open to this campaign as I know many people who like us both.”

Scott Santens, a fervent advocate of universal basic income, said Sanders’s campaign revealed that Sanders “is afraid of Andrew Yang” by making “a strategic move here to lie by omission to make Bernie look better.”

“The more I think about this, the bigger a deal it is to me. Bernie’s campaign made a strategic move here to lie by omission to make Bernie look better. In other words, Bernie Sanders is afraid of Andrew Yang, and holy secure bag, that’s a serious achievement by the Yang campaign,” Santens tweeted.

There were more signs this weekend at California’s Democratic convention that Sanders’ supposed “clout in the party might be overrated,” as the the Washington Post argued after a Sanders-backed candidate resoundingly lost her race to become the party’s new chair. As the Post noted, “the main work of the convention was not the presidential contest; it was a race to elect a new chair of the largest Democratic Party in the country.” And the fact that Sanders could not get his candidate elected at a convention of progressive activists in a far-left state meant that, according to the outlet, “some of the influence of Sanders supporters in the party had declined” and activists were less enthusiastic about taking on and defeating the party’s establishment.