I hate to say it, and I've avoided saying it, so as not to trigger any Democrats on here who were identified "boy" at birth. But the reason there is a gender gap is that the Democrat party has run away from typical men. Their entire focus is on "transmen," gay men, and beta males who would prefer to have normal relations with women, but who have been convinced that the way to succeed with them is to do things like carrying tampons in case a girl has an emergency need.
There are real men who vote Democrat because they aren't paying attention to what Democrats have been doing the last ten years. They base their votes on the anti-Republican rhetoric that passes for news, and Democrat ads in which they pretend to be conservative. Males who are vocal about their support of Kamala Harris, et al, are almost exclusively some kind of atypical sexual deviant, whether they are open about it or not.