In several states adultery is still illegal, though I believe a misdemeanor in most, in some (Idaho, for one), it's a felony.
Regardless of how few people have been sanctioned criminally recently (and fun fact, in some of those states adultery is a crime only a woman can commit...), very very few politicians want to be the one to formally repeal laws against "the sanctity of marriage", however antique they may be.
Regardless of how few people have been sanctioned criminally recently (and fun fact, in some of those states adultery is a crime only a woman can commit...), very very few politicians want to be the one to formally repeal laws against "the sanctity of marriage", however antique they may be.