Is calling someone a egotist a typical liberal slam of the successful business man.
It’s a flexible term with multiple uses.
;-)
In this case it’s used to describe a guy who screwed up so badly there was no way to recover and win, but who chose to continue (rather than do the right thing and drop out) because he was either egotisticallt delusional and thought he could win, or egotistically self-aggrandizing and wanted the attention (even if it was negative attention) associated with being a Senate candidate to continue.