On June 28, 1949 the Vatican issued a decree that laid down an excommunication of anyone who professed atheist and materialist communism and condemned supporting the communist party.  Ten years later on March 25, 1959 an extension was added to the decree which condemned anyone who votes for the communist party or for any party supporting it.  We at Christ the King Law Center (CKLC) believe that just as Catholics could not vote for the Communist party they cannot today vote for any political candidate of the Democratic party. We believe this because, amongst the two viable political parties in the United States today, the Democratic Party is at least the greater evil.
The Democratic Party platform  supports and not merely tolerates abortion as opposed to the Republican Party which wants to restrict most, if not all, abortions. The Democratic Party's platform states that it will "stand up" for Planned Parenthood funding by the government, describes abortion as "core" to people's "health and wellbeing", "vows to "overturn" state and federal regulations on abortion such as the Hyde amendment. Repealing the Hyde amendment could have a devastating effect on the lives of many other unborn children as the Hyde amendment has been credited with saving the lives of more than two million unborn children.  The Democratic Party's platform also states that Democrats will "combat any acts of violence, harassment, and intimidation of reproductive health workers, patients, and staff." Thus the Democratic Party seeks to curtail the free speech rights of pro-life protesters under the excuse that they are "intimidating" and "harassing" abortion workers. The Democratic Party platform repeats Hillary Clinton's position to appoint judges "who will protect a woman's right to safe and legal abortion." This would mean the Democratic Party seeks to try to preserve Roe v. Wade and other pro-abortion decisions of the US Supreme Court. The Democratic Party believes that "[s]afe abortion must be part of comprehensive maternal and women's health care and included as part of America's global health programming." This means that the party seeks to have the United States government promote abortion overseas.
In contrast the Republican Party platform  affirms "that the unborn child has a fundamental right to life which cannot be infringed." Thus the Republican Party aligns itself with the Church on the issue of the right to life. The Republican Party platform also calls for a constitutional amendment protecting the unborn and "legislation to make clear that the Fourteenth Amendment's protections apply to children before birth". Section 1 of the Fourteenth Amendment states that "[n]o State shall... deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws." Since science, reason, and divine revelation clearly shows that unborn children are persons then the protections of the Fourteenth Amendment to provide equal protection and due process applies to the unborn and prohibits the state from permitting their lives to be taken by abortion while the lives of those that are born are protected by the laws and institutions of the states. Section 5 of the Fourteenth Amendment states that "Congress shall have power to enforce, by appropriate legislation, the provisions of this article." The Republican Party goes further by calling for defunding planned parenthood. This is the first time that the party has called for the defunding of the abortion giant.  In contrast with the Democratic Party's understanding of judges the Republican Party platform calls for appointment of judges who "respect traditional family values and the sanctity of innocent human life." Such a statement is admirable, to say the least, since it distinguishes between "innocent human life" and "human life" and thereby permits the death penalty which Church doctrine clearly permits.  Other parts of the Republican platform calls for the banning of the sale of fetal body parts and tissue, opposing the funding of healthcare with abortion coverage, supporting adoption, funding for ultrasounds, supporting other regulations on abortion such as informed consent, parental consent, waiting periods, clinic regulation and other regulations. And finally the Republican Party platform goes beyond abortion and states that they oppose euthanasia, assisted suicide, embryonic stem cell research, and human cloning. All of these things are opposed by the Church and are violations of the 5th Commandment which states "thou shalt not kill."
Therefore the Democratic Party platform supports and not merely tolerates abortion while the Republican Party wants to restrict most, if not all, abortions and therefore no Catholic should vote for a Democrat for any political office. Some may object to our judgment and say that the Republican Party is not good either and Christ the King Law Center (CKLC) has already stated its dissatisfaction with Republicans here and here. However on those issues where we have expressed dissatisfaction at the Republican Party the Democratic Party is ether no different or worse. The Democratic Party has no more interest in supporting the Social Reign of Christ the King than does the Republican Party. At least with the Republican Party we can get a government that respects the laws of God with regards to marriage being only between a man and a woman, protection for the lives of the unborn and greater freedom for the Church. Therefore in the name of our most High King Jesus Christ we urge Catholics to not vote for the Democratic Party!
 R. Amerio, Iota Unum: A Study of Changes in the Catholic Church in the XXth Century 255 (1996).
 The Democratic Party platform can be found here.
 See here: https://www.lifesitenews.com/news/the-hyde-amendment-saved-two-million-babies-from-death.
 The Republican Party platform can be found here.
 See here: http://www.lifesitenews.com/news/for-first-time-republican-party-platform-proposes-defunding-planned-parenth.
 See here: http://cklc.weebly.com/blog/can-the-church-ban-capital-punishment.