The over representation argument comes in when other groups are "underrepresented".

The larger point was that in the US, white Americans were not being discriminated against. Their Ivy League enrollment matched their share of the population. There is a belief among many white American males that they are being discriminated against. The statistics don't bear that out. 

What is clear that there is less discrimination for them. Therefore CEOs, professional employees, and even Presidents, are more likely to be female or minorities. But white males will still be over represented in the top for a few more decades.