When the attorney lobbies to have the Solicitor General water down the administration brief to say that diversity is a compelling interest to justify discrimination, then I dare say he approves of affirmative action.
Right there you reached a conclusion without examining facts. You are assuming, or even presuming, that the mere consideration of an individual's race amounts to discrimination. The University did not use quotas, which meant that there was not a situation where a more qualified individual would have been passed over in favor of a less qualified individual, based on their race, in order to satisfy a quota.
When the solicitor general loses an argument to the attorney, then I say that the wrong guy has the job of solicitor general.