He’s a gun grabber. He’s doing the election promise shtick. If elected, he’ll pursue it.
And how are you so certain ? Because Kennedy is always talking about how guns are not the problem, there have always been firearms, he was even in a gun club in high school so the issue is more cultural and mental health related. He does mention students taking SSRI’s of course (being interested in the science side of policy) and a side effect of psychiatric drugs as homicidal or suicidal ideation although I’m not personally convinced that is a factor in most school shootings. He is at least bringing that into the discussion and asking for more studies (or any studies, really).