A statement was made at a pro-life anti-abortion rally by a Jew wearing a kippah that NO Pro Lifer would kill Hitler ימ"ש when he was a baby if given the chance because he was just a baby. This statement has received a lot of criticism on social media.
This person - with all do respect for his considerable oratory skills and high intelligence [and if I may say - good looks!] - he does not represent Jews or Torah. He speaks for himself - always. I think most people's gut reaction is that if they KNEW that baby Hitler was in front of him, they would HAPPILY kill him - with a bracha [ברוך שפטרני מעונשו של זה?]. Pashut.
It should also be noted that Rav Chaim Ozer Grodzinski [Shu"t Achiezer 3/73] and other Acharonim as well say that a FUTURE rodeph ["halachic pursuer"] is also considered a rodeph even if at this time he is a danger to nobody. A fortiori [קל וחומר] for a monster like Hitler for whom the term rodeph is the highest compliment ימ"ש לנצח נצחים.
Based on the principal that a future rodeph is also classified as a rodeph, we can answer the question of the קבא דקשייתא קושיא א who asked why we aren't מחלל שבת to save a rodeph upon whom an avalanche of stones [גל של אבנים] fell. He is no longer a rodeph?! The answer is that NOW he isn't, but if you save him he will be....
THAT is one meaning [here is another] of the puzzling pasuk in tehillim
Who is the baby that we wish to grab and to smash to pieces on a rock? A baby who will turn into Hitler.