The long standing Catholic moral principle of double effect does not presuppose they are. Another way of putting what Ken Briggs is trying to say is that the End does not justify the Means or it is immoral to select an Evil Means to achieve a Good End.

It is sound, traditional Catholic ethics to argue that it would be immoral to choose the means of electing Trump to achieve the Good End of ending abortion, if it is known and predictable in advance that President Trump is likely to, among other evil things, overturn Obamacare which will in turn cause thousands to die before their God-intended time because Trump has taken away their medical coverage. 

Not really all that complicated, although very badly stated in this article. Complicated only iifone holds that the life of the unborn is more valuable the the born but sick the Trump's policies are going to cause. Is that what you mean when you say the lives taken are not equal?