Emailing a professor for points on an exam when you want a recommendation from the professor

Let it go.

You discussed this before, he made his arguments and it is unlikely that he will change his mind. It isn't only up to you to make a good argument for the points, but the professor himself will have judged the points again when you discussed them and will now be convinced that the points are fair.

Begging even more for the points will probably not get you any more points, but may annoy the professor, e.g, because you already discussed it and you are still not satisfied after he told you the final outcome. He has neither the time to discuss this again and again, nor he will consider that he was wrong the first two times (the first assignment, then your previous discussion).

At U.S. top schools, recommendation letters are more important than grades.

If your professor knows you well and has a truly positive opinion of you, this will come out in the recommendation letter. The best thing you can do for yourself cultivate a real relationship with the professor (e.g. by visiting office hours, talking about ideas beyond the syllabus of your class etc). If you can talk about your goals for doing original research, so much the better.

As an aside, perfect grades aren't a very strong signal for who will be a good PhD researcher, so I really wouldn't worry about the grades very much anyway. A person who is curious and pushes themselves beyond their comfort zone -- even at the risk of getting some bad grades -- is a much better PhD admit than someone who has always gotten perfect grades.

If you asked me for the points and the letter, i would give you the points and reflect my irritation with you in your letter.