You need to read your own articles. It's clear that he was "pressured," which we all experience in all areas of our lives, and acting in response to the pressure from others is often appropriate (but sometimes it isn't). People in his own party can say what they want, even in public. There's nothing illegal, against the rules, or even immoral about that. In fact, I think more people need to speak out against their own party like Nancy Pelosi did in this case and Adam Kinzinger did against Donald Trump.
You know what's the funniest thing? Republicans were all saying that Biden was completely incompetent and shouldn't be a frontrunner for President. However, then they complain when he steps down and gets replaced by the Democrat Party.
You seriously can't make this stuff up. I think we're living in a matrix.