Hard to say what's causing this. try "is abortion good or bad" on Google vs Bing and you get very different results. Bing provides evenhanded results and Google is almost entirely pro-abortion.
It's pretty easy to say what's causing this, as I've given the exact reason why and shown two non-US search engines with the same behavior.
As far as your abortion example, Bing very clearly took an editorial decision to put its thumb on the search results ranking, going so far as showing a "vs." with two different articles at the top. Google just let its default relevancy algorithm do the ranking, which means articles that contain both the words "good" and "bad" will tend to rank higher than articles that just contain "bad."
The exact same checks apply to this case to throw out the Google bias argument as right wing outrage hysterics targeted at simpletons who don't know how to verify the assertion. My Google results contain two first page links that say without argument that abortion is bad. Both Yandex and Bing have 0.
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