While the push for an ever-expanding approach to modern space exploration has arguably been kept in the mainstream in recent years thanks in large part to Elon Musk’s SpaceX projects, many have remained skeptical of Musk—also known for Tesla, The Boring Company, Neuralink, and his support of bitcoin—due to capitalism’s proven societal shortcomings.

Over the weekend, Musk responded to a Clean Technica piece titled “Attacks on Elon Musk for His Wealth Are Ridiculous,” stating that his aim was to build up resources for an eventually “multiplanetary” existence.

“I am accumulating resources to help make life multiplanetary & extend the light of consciousness to the stars,” Musk said on Sunday.

The article in question, penned by Zachary Shahan, specifically criticized a recent tweet from Vermont Senator Bernie Sanders, who said last week that Musk and Amazon CEO Jeff Bezos’ level of wealth was both “immoral” and “unsustainable.” And shortly after Musk replied to the article, Sanders hopped back into the discourse.

As Sanders explained, space travel is indeed “an exciting idea,” but—in his opinion—the larger focus should remain on creating a progressive tax system that helps everyday people here on Earth first and foremost.

“Space travel is an exciting idea, but right now we need to focus on Earth and create a progressive tax system so that children don’t go hungry, people are not homeless and all Americans have healthcare,” Sanders said on Sunday “The level of inequality in America is obscene and a threat to our democracy.”

A few hours prior to his Musk response, Sanders shared a tweet highlighting the disparity between CEOs’ pay growth between 1979 and 2019 and workers’ pay growth during the same time period:

Earlier this month, Sanders was among the lawmakers who backed the new Ultra-Millionaire Tax Act, which—if put into motion—could bring in at least $3 trillion in revenue over a ten-year period by way of a two-percent annual tax on the net worth of households and trusts between $50 million and $1 billion, as well as an annual one-percent surtax on the net worth of households and trusts over $1 billion.

“As Congress develops additional plans to help our economy, the wealth tax should be at the top of the list to help pay for these plans because of the huge amounts of revenue it would generate,” Senator Elizabeth Warren said at the time. “This is money that should be invested in child care and early education, K-12, infrastructure, all of which are priorities of President Biden and Democrats in Congress.”

Sanders co-sponsored the Ultra-Millionaire Tax Act alongside Sheldon Whitehouse (D-R.I.), Jeff Merkley (D-Ore.), Kirsten Gillibrand (D-N.Y.), Brian Schatz (D-Hawaii), Edward J. Markey (D-Mass.), and Mazie Hirono (D-Hawaii.).

Also this month, Musk and Tesla CFO Zach Kirkhorn announced their new titles of Technoking and Master of Coin in an SEC filing.