I think you phrased that incorrectly, hopefully not intentionally in bad faith. What you mean is that something like 94% of teacher's unions political contributions go to democratic politicians. It is certainly untrue that the biggest contributions to democrats come from teachers, and it is trivial to find that out.
I am also skeptical that phonics is why teachers prefer democrats. It probably has a much stronger association with how villainized educators are by republicans.