William O. Douglas had a debilitating stroke 11 months before he finally retired from the Supreme Court. After that he kept trying to go to work and became angry when his clerks were reassigned. It's possible a stroke would make Biden even more stubborn, and the Democrats are too cowardly to go through with the 25th Amendment.

One commentator has attributed some of [Douglas's] behavior after his stroke to anosognosia, which can lead an affected person to be unaware and unable to acknowledge disease in himself, and often results in defects in reasoning, decision-making, emotions, and feeling.