if i were trump, i'd react to mamdani mostly by making fun of new yorkers for it. new york should truly be embarrassed for electing a loser like this guy, and i'd be merciless in ridiculing them for it.
the first thing i would do is announce a $10 million dollar grant to the new york city health department for education and outreach regarding the negative public health impacts of poor sanitation practices in relation to male facial hair hygiene. clearly, new yorkers need a bit of a public health tutorial on the topic.