When I express my opposition to abortion, I have often been branded a "one position" voter. For me abortion isn't an issue with a stance, it's a character test. If you tell me you support abortion or that you are pro-choice, then I know everything I need to know about your character and your wisdom.
I was told on this very forum by a pro-Trump fellow that I was a "one issue voter." That was a lie, since there are many, many issues which are important to me, but I completely agree with you that it is not a political view.
Your referring to it as a character test, is completely accurate. If you don't value the life of the unborn (or the elderly, in end of life issues), you are missing some very important discernment, and yes, both character and wisdom.
That is why I have known for a very long time that Donald Trump doesn't have the character or integrity to be President.
Even if he picked a nominally pro-life VP, he is on the wrong side of what determines the character of this nation.