Why do so many people answer an attack on their politician by ignoring the issue and instead attacking the other party?

zagor
For instance, if you criticize President Biden for something, they bring up the transgressions of Donald Trump. Or vice versa. And assume you must be from the other party.

If they can't defend their candidate on the issue involved they should just STFU and not assume you support some particular other candidate.
Why do so many people answer an attack on their politician by ignoring the issue and instead attacking the other party?
12 Opinion