Democratic presidential candidate and former Vice President Joe Biden says that any of his colleagues, or even a cartoon mouse, could realistically beat President Donald Trump in the November general election.

Biden's remarks were made during a Tuesday morning appearance on MSNBC's "Morning Joe" while discussing Democrats' prospects in November.

Referring to some recent comments made by longtime Democratic consultant James Carville, co-anchor Willie Geist asked Biden if he thought that if Sen. Bernie Sanders (I-Vt.) is the eventual presidential nominee, Democrats will lose the election.

"I refuse to suggest any Democrat can lose," Biden responded.

"I think we could run Mickey Mouse against this president and have a shot," he added to applause from the audience.

While he may have meant it to be a dig at Trump, Biden's argument undercuts the electability case his campaign has previously made to Democratic primary voters — i.e., that he's the only Democrat in the field who can take the president head on and win in the general election.

Biden's purported ability to beat Trump in an election has been a central theme of his campaign so far.

"I think that for the first time in my career, the person viewed as who is best capable of defeating this president rises above the test of, 'I have to agree with the person 100 percent,'" the candidate said in August. His first campaign ad in Iowa from around the same time argued that "no one is more qualified" to oust the president from the Oval Office.

"If Joe Biden wins the primary, he can beat Trump in a general election," a Biden campaign email said in November. "Other candidates can't."

Biden's wife, Jill, also made the electability case to voters in Iowa last month. But, if any Democratic candidate or even a fictional character can supposedly beat the president, that case doesn't really hold all that much water anymore.

Meanwhile, Biden's supposed electability has also been undercut by a weak showing in Iowa and some new polling. On the eve of Tuesday's New Hampshire primary elections, Quinniapac released numbers showing a 9-point decrease in his support in less than two weeks.