I don’t get it. Why do they even care?
Under Orthodox Jewish law, only a husband may give a religious divorce ("get") to his wife; a wife cannot divorce a husband. So when an Orthodox Jewish couple get a civil divorce, the wife cannot remarry unless the husband also gives her a religious divorce; if she does remarry, she is considered an adulteress. Some unscrupulous husbands refuse to give the religious divorce in order to pressure their ex-wife to give up alimony or child custody.
Because he is Republican and/or Jewish, is my guess.