Well, when one is voting for Trump, one is voting for some evils that come along with him (that have been adequately docuмented on this thread).  So, for instance, one is voting for someone who condones and even glorifies sodomy.  At the same time one is voting for someone who has shown some commitment in favor of the unborn.  So there's some good, and there's some bad.

But what a Catholic voter does is to promote the good (anti-abortion) while also at the same time recognizing that there's evil that has come along with it.  So, for instance, the classic case of double effect is to perform an operation in an ektopic pregnancy to save the mother's life, knowing, however, that it will cost the life of the unborn child.  Even such an operation has to be performed very carefully so that one does not directly take the life of the unborn child, but, rather, removes the thread to the mother, without directly causing the death of the unborn child.  So the question of double effect with Trump is whether one's vote actually directly causes the evils that might be promoted by Trump during a second term.  This is where the application of double effect to voting becomes murky, and this really needs to be developed by Catholic moral theologians.  It's an extremely neglected aspect of Catholic moral theology.

Not for Catholics.  "Lesser of two evils" is contrary to core Catholic principles.  Catholics think in terms of "double effect."  I'm not sure how many times i need to repeat this.  Catholics can never do evil even to prevent a much greater evil.  But Catholics may make a choice with an intended good outcome even if unintended bad outcomes might result as well ... if certain conditions apply.

I understand what you are saying. BUT CAN YOU SHOW ME WHERE YOU ARE FINDING THIS??? Prior to Pope Leo XIII, the Catholics were taught to not vote in the elections of Italy due to Socialism.  I can see your point that you speak of here. Now again Pope Leo XIII had a different view and that view was the Catholics needed to vote. Again Pope Leo said in an election with two Socialists you must vote for the lesser of two evils. Pope Pius XI scolded the Catholics in Germany for sitting out the election and said this is why Adolph Hitler was able to be placed in power. I have cited my sources previously to my points in Canon Law Study for Catholics voting.

 Pius XI was also the man who betrayed the Cristeros.

The story of the Cristeros, alas, is not one of victory. That does not make it less than inspiring, however, for if they finally laid down their arms, they did not really surrender to the Revolution against which they fought. Militarily they had brilliant successes, and that they could ultimately have prevailed in the field is possible. In May, 1929, it even looked likely. However, they lacked the support they deserved. This is not to speak of popular support, for theirs was already genuinely a popular rising. What was missing, except at the very beginning (and which was not of a practical nature even then) was the support of the bishops of the Church in Mexico. Missing too was the support of the Holy See, which had once thundered against the regime in Mexico City, but that was before a deal was reached with it, a deal fatal to the Cristeros. Insofar as the bishops and Holy See went the route they did, instead of supporting the Cristeros, it could be said the peasant-warriors were betrayed by the very men for whom they fought. 

Betrayed they were.

Sure it was God's will in the end, just like the consequences of any error or sin.  So, for instance, if a man murders someone, it was God's will that the victim die that day, even if it wasn't God's will that the perpetrator commit that sin.

Pius XI, like Benedict XV before him and Pius XII after him, was a diplomat and was too ready making deals with the enemies of the Church.  Regardless of his intentions, this was an objective betrayal.  It goes without saying that only God can judge his intentions.
Benedict XV through Pius XII, unlike St. Pius X, were constantly extending olive branches to the enemies of the Church, both political and theological, and this all lead up to Vatican II.

No, the expression that's faulty is "lesser of two evils" ... that is not Catholic and is equivalent to "end justifies the means".  It's Catholic moral theology 101.  You cannot do an evil even to prevent a much greater evil.  One can vote for the less defective candidate based on double effect.  Cite Pope Leo XIII on this point instead of paraphrasing.  I've seen repeated anecdotal references but never an actual citation.  As for Pius XI, there's no reference to who the alternate candidate was.  Again, citation please.  Frankly, had I been a German, I might have voted Hitler at the time, since his platform was one of nationalism more than anything else.  Pius XI was also the man who betrayed the Cristeros.

If you want to vote for Trump, it can be done, but please use Catholic language and rephrase it as an exercise in double effect.  Constantly using the utilitarian "lesser of two evils" phrase can be pernicious.  It's the same reasoning which would have some people think it's OK to kill a couple innocent people in order to save millions.  There was a TV show some years ago in which a terrorist threatened to unleash a nuclear weapon on a city if the U.S. agent did not kill another agent (who was innocent) ... because that agent was getting too close to finding him.  So the guy did it.  Too man Catholics might start reasoning that this would be OK and start warping their Catholic sense for moral theology.  It's not any kind of dilemma.  You are not permitted to take that single innocent life even if it's to potentially save millions.  You cannot perpetrate that evil even to prevent a greater evil.  You cannot do the "lesser evil".

No one is accusing him of having been malicious.  But it's quite clear that the Popes after St. Pius X were softer on Modernism, trying to make peace with the enemies of the Church, and this had devastating consequences.

Terrible mistakes were made.  And Pius XII even made terrible doctrinal mistakes, like opening the door to evolution and to natural birth control.  He also appointed all the Modernist/heretical bishops who would later bring us Vatican II.