I don’t think this should be a poll. That would imply that there is more than one option. It is not up for us to say what is a mortal sin. Just ask someone from the Church who knows the answer.
The church can’t, doesn’t, and shouldn’t, have a pat answer for every possible situation we might face that has moral consequences. Rather, she proposes general guidelines we should learn, with some (relatively few examples) of how to apply them.
Evangelium Vitae 73 proposes such a guideline. It can’t, however, be viewed in isolation. It is part of a large body of discussion of moral principles that has been developed over two thousand years. This body of discussion includes generally accepted (by orthodox moral theologians) principles such as the “Principle of Double Effect” and the principle of the “Lesser of Two Evils”, among others, that may apply to a particular circumstance, such as whether or not a voter may vote for a politician who believes in legalized abortion.
It is the job of the Catholic Church to teach these principles and how to apply them.
It is the job of the individual to learn the principles and to actually apply them when encountering situations of an unclear moral nature.
It is unreasonable to expect the Church to speak definitively on every single moral question of the day with an infinite number of nuances that might affect the licitness of an action.
These are complicated questions. It is reasonable to expect that good and reasonable people will come to different conclusions based on reason.
It is an abrogation of one’s personal responsibility to ask the Church to make every moral decision for you.
The people on this forum are trying to discuss this important issue so that they can inform (and form) their conscience properly. They are doing the “due diligence” the church asks of us.