U.S. Senator and former presidential candidate Bernie Sanders urged his progressive supporters to vote for former Vice President Joe Biden on Boston Public Radio Thursday, citing Biden's proposed response to the COVID-19 pandemic as one key factor, as cases surge across the country just days before the election.

"Bottom line is, Biden will listen to the science, help us with guidelines that will effectively combat this terrible pandemic," said Sanders.

While Sanders pushed for significantly more progressive policies while running himself, the self-described democratic socialist said the choice is clear: Four more years with President Donald Trump at the helm is unsustainable.

Sanders called Trump a "pathological liar ... a racist, a sexist, a homophobe, a xenophobe," who is "literally trying to undermine American democracy."

And Biden, said Sanders, has built a platform that is "reasonably strong" for working families, that will be paid for through "progressive taxation — telling billionaires in this country they cannot get away with having an effective tax rate that is literally lower than working people."

Should Biden win, Sanders said he expects progressives will have a seat at the table in his administration, "so that we can express the views of tens of millions of progressives in this country who want the Biden administration to stand up to corporate greed, to stand up to the fossil fuel industry, the prison industrial complex, etc."

"We can't get it all, we lost the election, I know that, but we are an important part of [the Democratic] coalition, our voices and our ideas must be heard as we develop public policy," he said.

While Sanders on the campaign trail had said he does not support expanding the Supreme Court, he said Thursday that Biden's proposed commission to examine Supreme Court reform is "not a bad idea."

"It's important that we figure out a way to have a Supreme Court that does what it is supposed to do," he said.