 Supporters of a potential ballot question that would do away with the graduation requirements of the high school MCAS exam will show off what they believe gets them to the finish line. 170 signatures ready to be dropped off at Secretary of State Bill Galvin's office. They'll rally at the State House steps today. The Mass Teachers Association has long been behind the movement, suggesting that a single standardized test does not measure the depths of a student, and many are denied diplomas when scores don't add up.