I agree that Land believes he can get away with more in the southern US among friends, it doesn’t make him any more appropriate.
He is a public figure for a major denomination that spans the globe.
SBC blog posts and comments are interesting. Not many are defending him.

He was crass and vulgar, he’s been to Oxford and Princeton and he knows exactly what he said. If he said what he did in Christian circles in Canada, I’d like to think no one would be laughing and would speak up. We have a sorry history of anti-Semitism. I suppose some would shrug it off and give him a pass, and that would be to our shame.

“…solely in an attempt to employ a word that alliterated with Schumer’s name…”

Is it offensive to say that’s fancy bull merde? Out of the heart, and when in doubt…his none apology just ups his creepy level.

Land’s comment would have gotten his mouth washed with soap in a Yiddish household, for it is Yiddish for, ahem, a certain part of the male anatomy. Just as an English slang for the organ can be use (the one that is part of Richard Nixon’s nickname) can be used as a synonym for “jerk”, such is the use of schmuck here.

Through Jewish comics and others, that term has gotten into common usage in the latter 20th century in American Gentile culture.

I think the phrase “Don’t attribute to malice what can be better attributed to stupidity” applies here. There may have been “Jewish guy, use a Yiddish put-down” meme going, but Land was probably after Schumer as a liberal, not a Jew, dissing both New York senators in one sitting.