The SEC is basically trying to argue that the speech was personal opinion (and the speech said that ETH was not a security), but Ripple alleges that the speech, though perhaps not an official statement, was much more than a personal opinion. We now know the SEC lawyers were involved in writing the speech, which is making life difficult for the SEC. This is also why the SEC is being far more careful now and is saying only BTC is not a security, but that ship may have sailed.
It's being called the Crypto Trial of the Century. A win for Ripple on the SEC's slip-up could mean the SEC is powerless to intervene in most crypto markets. A win for the SEC would result in mass regulation.