Today, the Supreme Court unanimously upheld the three-judge district court's decision in Evenwel v. Abbott.  While the media and the left are trying to paint this decision as a victory for Democrats, it merely upheld the status quo around the country:

The Supreme Court ruled Monday that states can draw state legislative districts based on total population, rejecting a challenge that would require districts to be equalized by another criteria, such as registered voters. 

The ruling essentially maintains the status quo nationwide, as almost all states use total population to redraw their state districts based on the “one-person, one-vote” principle. The justices ruled narrowly, however, and did not finally resolve whether states could choose to use a different metric to draw districts in the future. 

The language of the decision also appears to further solidify that congressional districts will remain drawn by counting everyone in their borders as a “person,” which is the basis in the Constitution for deciding how many congressional districts each state gets.

While many conservative, libertarian, and right-leaning organizations filed amicus curiae briefs in support of the appellants, notably, no Republican organizations such as the National Republican Campaign Committee (NRCC) or Republican State Leadership Council (RSLC), which care the most about redistricting, decided to file briefs in the case.  

The Court left open the question of how a state must apportion its districts, so for now, both total population and total voting age population remain acceptable means of apportionment.  The Court’s decision today sided with Texas, a decidedly Republican-leaning state, and simply ruled that the way Texas had apportioned its districts was constitutionally acceptable.