Final answer:
The Democrats made major changes to the presidential nominating process after the 1968 Chicago convention. These changes were aimed at democratizing the process, requiring delegate allocation based on state primary performances.
Step-by-step explanation:
After the 1968 Democratic National Convention in Chicago, where there was significant chaos and criticism of the delegate selection process, the Democratic Party instituted major changes in their presidential nominating process. The new rules, guided by a commission led by George McGovern, required that delegates be awarded based on candidates' performance in state primaries. This necessary change emerged from the turmoil during the 1968 convention and Nixon's subsequent re-election strategy that showed a need for a more democratically influenced primary process. Overall, the process was reformed to ensure that a candidate who won no primaries could not receive the nomination, unlike what had happened during the contentious 1968 convention.