David Stern was an extremely successful commissioner of the NBA. The mark he left helped set up the NBA for the massive levels of success it enjoys today, but there are a few blemishes on an otherwise perfect record. Pushing through the NBA dress code and allowing the SuperSonics to leave Seattle come to mind. However, none are as infamous as the Chris Paul trade veto.
New Orleans was without an official owner when it came time to trade Paul. The NBA had purchased the franchise from owner George Shinn due to his financial troubles and this left the NBA as acting owners of the team. When the Hornets put together a deal that would have sent Paul to the Lakers, Stern vetoed it for "basketball reasons," claiming the trade was not fair compensation. Paul was eventually moved to the Clippers instead.
For years, Stern has been accused of abusing his power for not allowing the Lakers to receive Paul. Stern, however, defended himself on a podcast recently that Los Angeles still had a chance at Paul but that Mitch Kupchak panicked and traded away Lamar Odom.
"(My decision) was only based on what was good for New Orleans, or what was not good for New Orleans. It had nothing to do with the Lakers at all. And, in fact, in the course of the weekend, we thought we could re-do the deal. We really thought that Houston would be ready to part with Kyle Lowry; and we had a trade lined up for Odom that would have gotten us a good first-round draft pick. Not we, but my basketball folks. But Mitch Kupchak at the time panicked, and moved Odom to Dallas. So the piece wasn't even there for us to play with at the time. So that was it -- just about what was good for the then New Orleans Hornets."
This side of the story comes exclusively from Stern with no input from Kupchak, so maybe it's true that he was trying to look out for New Orleans. Most who have an opinion on Stern's decision one way or another are dug in and aren't going to let his arguments now change what they think.