Every four years, Catholics face an intense dilemma in regard to the vote. There are ardently Catholic Democrats who wonder how their co-religionists could possibly choose a Republican candidate, and there are ardently Catholic Republicans who express precisely the opposite opinion. And both sides, typically, look with eagerness to their bishops and priests to resolve the tension. Each presidential election cycle, the Church endeavors to clarify the issue, usually to the satisfaction of very few. However, under the rubric of "once more unto the breach, dear friends," let me try to provide some direction by articulating four basic principles.

First, Catholic social teaching clearly goes beyond the split between Republican and Democrat, between liberal and conservative, and therefore corresponds perfectly with neither political camp. Anyone who says that either of our political parties perfectly, or even adequately, represents Catholic social thought is simply misinformed. Broadly speaking, the Democratic Party advocates a number of themes and principles reverenced by the Catholic tradition: concern for the underprivileged, for the migrant and refugee, and for the environment, as well as opposition to capital punishment and to all forms of racism. And again, broadly speaking, the Republican Party sides with Catholic teaching in a number of ways: opposition to abortion and euthanasia, defense of the traditional family, advocacy for conscience protection and freedom of religion. Which of the two parties is more "Catholic?" It seems to me impossible to adjudicate the question in the abstract.

Are we left, therefore, simply in a lurch? Not quite, and this leads to the second principle I would like to explicate: among the various values mentioned, a priority must be given to the defense of human life, since life is the most fundamental good of all, the one without which the other goods wouldn't obtain. Therefore, in the political calculus of a Catholic, opposition to abortion, euthanasia, and capital punishment should take pride of place. Now, just to keep things complicated, Republicans are relatively right in regard to the first two and Democrats in regard to the last one, though, to be sure, the number of those threatened by abortion and euthanasia is far greater than the number of those under threat of capital punishment. Sometimes people will say that all lives are equally sacred, but in this context, that observation is something of a red herring. For the relevant question is not which lives are more sacred -- those of the unborn, the elderly, the poor, the migrant -- but which lives are more direly and directly threatened.

And this leads to a third principle: a Catholic may never vote for a candidate because that candidate supports a morally repugnant position, only despite that support and only because of balancing considerations. Thus, for example, a Catholic in good conscience could never say that she will vote for Joe Biden because the Democrat is pro-choice, and by the same token, a Catholic in good conscience could never say that he will vote for Donald Trump because the Republican is for capital punishment. Each would have to say some version of "despite his unacceptable position, I will vote for him because, in prudence, I have determined that other commitments of his and/or his own character counter-balances his objectionable opinion." Does this lead us into somewhat murky waters? Frankly, yes, but that's necessarily the case when we're dealing not with matters of principle but matters of prudence.

And this last statement conduces to my fourth and final proposition: Catholics ought never to disagree in regard to moral principles, but they can indeed legitimately disagree about the best means to instantiate those principles. So, for example, I think that every Catholic in America ought to embrace the political ideals that I identified above, some more characteristic of the left and others of the right. Every Catholic ought to be for protecting the environment, serving the poor, defending the traditional family, battling social injustice, advocating for religious liberty and freedom of conscience, etc. But not every Catholic is obliged to subscribe to the same means of attaining those ends. Liberal and conservative Catholics can disagree about the Paris Climate Accords, the legitimacy of off-shore drilling, the advisability of reforming our health-care system, changes to our tax laws, the level of the minimum wage, the best policy in regard to Wall Street regulation, etc., etc. Those latter issues are open to legitimate debate and are matters for prudential judgment.

Perhaps I might, in closing, not so much propose a fifth principle, as deliver myself of a "cri de Coeur": Vote! Some Catholics are tempted -- and I will admit to feeling the tug of this temptation -- that because things are so complicated politically for those who advocate Catholic social teaching, it is best to say, "a plague on both your houses," and keep to the sidelines. But this is not a tenable position. In the Lord's Prayer, we petition, "Thy Kingdom come, thy will be done on earth as it is in heaven." The Gospel message does indeed draw us ultimately to eternal life on high with the Lord, but it also has real-world implications here below. If we Catholics don't involve ourselves in the political process, as messy as that often is, we permit Catholic social teaching to remain a set of harmless abstractions.

- Bishop Robert Barron is the founder of the global ministry, Word on Fire, and is an Auxiliary Bishop in the Archdiocese of Los Angeles.