Democrats are talking about replacing Joe Biden. That won't be so easy.

ATLANTA, GEORGIA - JUNE 27: U.S. President Joe Biden walks off stage during the CNN Presidential Debate at the CNN Studios on June 27, 2024 in Atlanta, Georgia. President Biden and Republican presidential candidate, former U.S. President Donald Trump are facing off in the first presidential debate of the 2024 campaign. (Photo by Justin Sullivan/Getty Images)