What is the importance of the Supreme Court case of Reynolds v. Sims?

Basically it said that legislative districts across America needed to be equal in population. After R v S, over 30 lawsuits were filed against states claiming legislative apportionment schemes to be unconstitutional. Alabama's legislature, as an example, was using a population census from 1900. The plantiffs argued that the urban district of Alabama had grown significantly since that census and that this was a way of purposely diluting the district's voting strength. The larger the district, the more voting weight.