Joe Biden refused to answer a question on packing the Supreme Court in the first presidential debate because the former vice president is "afraid of alienating his far-left flank" and losing the election, Sen. Tom Cotton, R-Ark., told "Fox & Friends" Wednesday.

When Fox News' Chris Wallace, Tuesday night's debate moderator, pressed the Democratic presidential candidate on whether he would be willing to pack the Supreme Court and end the Senate filibuster, Biden flatly refused to take a stance on the issue.

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"Joe Biden obviously doesn't want to answer the question whether or not he will pack the court because his far-left flank wants to pack the court," Cotton said.

The senator, who made President Trump's Supreme Court nominee list, claimed a packed court would mean losing the right to religious freedom and Second Amendment rights, using tax dollars for abortion-on-demand up to the ninth month of pregnancy, and taking over a home to give it to a giant corporation to use as a parking lot, as a few examples.

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"That's what Joe Biden is dodging," Cotton explained.

"It wouldn't become the issue if he would have said, 'No I don't want to pack the court.' It would put the issue to rest. The reason he doesn't want to put the issue to rest by simply saying, 'No, I don't want to pack the court,' is because the Democrats have become so radical that they are willing to take unprecedented steps to fundamentally restructure the nature of our government to achieve their far-left agenda."

Trump, who nominated Judge Amy Coney Barrett over the weekend to fill the vacancy left by the late Justice Ruth Bader Ginsburg, jabbed at Biden when he refused to answer: "Who's on your list, Joe?"

Biden's running mate, Sen. Kamala Harris, D-Calif., also dodged the question in a recent interview, saying their campaign is focused on the days running up to the Nov. 3 election.

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"It makes no sense what they're saying," Cotton said. "They claim if they answer that question, it will be the central issue of the campaign for the next five weeks. Not if they say no.

"The reason why they don't want to answer it is clearly is in their hearts and they know on their left-wing flank the answer is yes. They do want to pack the court because they want to fundamentally restructure the nature of American government and that that would be extremely unpopular and probably cost them the election," Cotton added. "The American people should keep that in mind when they go to vote."