If you are only looking and middle and upper class educated students in America. The poor urban educated students are not given much in terms of STEM. My local school district gives no regular science class for K-5th grade students.
That said, STEM fields have historically sucked at diversity and outreach to disadvantaged populations. It's hard to do science with no budget for supplies. It's getting better(tm) with programs like FIRST.
This wasn't due to Common Core it is due to curriculum being mirrored by Standardized Testing.