What is the role of a PTA in a school?

The PTA is supposed to be a liaison between the parents and the staff of a school.
If the parents are upset about an executive decision that was made at your school in regards to class size being large and you as the PTA President have been asked to bring it as a new Agenda item at the next meeting is it to be ignored, as not a role of the PTA?
If you find out there might be a good chance that a class might have up to 40 students next year would that not be a PTA issue, or are we supposed to just ignore the fact because the Principal says there is nothing you can do about it, this is just the was it is going to be? Are we not supposed to question what is happening in our school, where are children are supposed to be educated, are we supposed to be quiet and just be steamrolled.
When the new Children's First intuitive was brought forth and we knew that this would be a disaster in the making, taking seasoned teachers out of our school was that not important?
This has been on ongoing situation in this school, it has happened before and it will happen again, the only difference is the parents in this school are vocal despite what we are told, and if we are to lay down and just take it next year all the classes will be 40 and then you can take your cushy top ten standardized math and reading scores and wave them goodbye.

Come one, come all

There will be a Press Conference on May 9th at 5PM on the steps of City Hall to protest the reforms that the Mayor and the Chancellor have proposed for our children. Since parent's have been left out of the equation here is your opportunity to let them know that we represent the unheard voices of our children. Who better to represent them but us.
Be there, I am going to be there the one with the Pissed Off look on her face.

I am so disappointed but the press conference has been called off.