And the reason they're all over the map, as it were ... is because not a single one has actually explained or thought through the principles involved. Instead, they're throwing out terms like "lesser evil," which are NOT valid principles of Catholic moral theology, without any nuance, distinction, nor explanation ... to the point that it's going to do damage far beyond the realm of voting, where in other scenarios Catholics will believe that one can make decisions based on the (utilitarian) consideration of doing the least damage and the most good, without considering for a second that it's all about the liceity of the means, and not simply a calculus about the final outcome. If someone wanted to explain why this is licit for reasons that do not contradict or violate Catholic principles, then I'm all ears ... but nothing of the sort has been forthcoming. Now, "double effect" is a licit Catholic principle, but no one (to my knowledge) has even attempted an application of double effect, but instead, merely double down on the liceity of "lesser evil", which is false, dangerous, and harmful.
This really isn't that complicated, and is very basic. Now, the Trad Catholics who promote lesser evil will sometimes (not always) put the term in quotes or air quotes (when speaking), realizing on one level that it is simply NOT a valid principle, but then applying it anyway without making any distinctions in terms of why suddenly it's OK when it's simply wrong.
Now, I surmise this is happening because the controllers, especially in America, have succeeded in persuading Catholics to somehow "compartmentalize" voting as if it were some kind of special animal where the normal rules don't apply. It's why you had so much Americanism, with US Catholic bishops insisting on separation of Church and State to be legitimate ideals (while then going and offering Mass on the Feast of Christ the King), or where JFK ran on the promise that his personal "Catholic" views had nothing to do with his political positions, platform, and policy. Somehow US Catholics believed that voting and politics were compartmentalized from their Catholic identities and operated on different principles and laws, rather than understanding that all human actions involve the same consideration of principles to determine their morality and liceity.