Every contemporary Christian politician (and judge) accepts the fact that there are activities that are perfectly legal and at the same time seriously immoral. The days when Christian morals were written into the law are past, and there is no "movement" to revert to past principles.
At the top of the list is abortion. The vast majority of Americans believe that (a) abortion is immoral, but (b) abortion should be legal, at least in some circumstances. There is no current political movement to outlaw abortion in all cases, and there is no chance that any future Supreme Court would do so through a court decision. But we survive.
Homosexual sodomy is universally condemned not only by Bible-believing Christians, but also by Orthodox Jews, Mormons, Muslims, and other religious groups, but there is no movement anywhere that seeks to reinstate the laws that condemn homosexual sodomy. Indeed, most Christians at least tacitly support gay marriage, from a legal standpoint.
Most religious people, Christians included, believe that many common, accepted activities are on the borderline of immorality...drug use (including prescription mood-altering drugs), alcohol abuse, gambling, gluttony, pornography, etc. And while preachers preach against these evils, there is no political movement to re-criminalize any of this.
To suppose that someone who is a Christian, or a Roman Catholic, and can't be trusted to enforce the law is either profoundly ignorant, or blatantly bigoted.
Which is why that meme is so popular on our Political Left