what is one possible reason that the supreme courts interpretation of equal protection has changed over time

The Supreme Court is more diverse

The Supreme Court itself is more diverse.

Explanation:

Formerly, all the judges of the supreme court were white and conservative homosexuals. For this reason, it was common at the time for these judges to have the same perspectives on egalitarian protection laws because judges were only able to assess problems related to their own ethnicity.

Over time, however, the group formed by supreme court judges began to become more diverse, as people of various ethnicities began to be part of this group. The entry of these people brought different and broader views and interpretations on egalitarian protection.