Whether the law is a good idea or a bad idea as written is another question, and is up to the legislature to debate that and amend the law as needed. But courts shouldn't be in the business of rewriting laws because they had some consequences that their authors didn't intend (although in this case I suspect that the original authors actually did very much intend for this sort of thing to be illegal also, since the laws were written back in the era where being color-blind was not considered bad).
Moreover, the plaintiffs commissioned a study on the effect color blind admissions would have on the racial distribution of Harvard's undergraduate population. It should be taken with a grain of salt, as should the materials offered by the defense, and I suspect it overestimates the effect a bit, but it conforms fairly closely with anecdotal evidence I've seen and so sounds much more plausible to me than the ACLU's take.
It claims the share of black students would shrink from ~15% to ~0.9% and the share of hispanic students from ~15% to ~3%. Meanwhile, the share of white students would shrink slightly from ~37% to ~35%. The proportion of Asian students would roughly double, from ~25% to ~50%.
Again, the specific numbers might be a bit off, but it generally agrees with a lot of anecdotal evidence I've seen --- being black or Hispanic gives one a large advantage, being white is close to neutral, and being Asian is a large disadvantage.
[1] https://www.npr.org/sections/codeswitch/2018/03/19/594993620...
[2] https://www.nytimes.com/interactive/2018/03/19/upshot/race-c...
There was a time that the ACLU would defend the right of Nazi's to march down a Jewish neighboorhood. Not because they thought that particular lawsuit would help anyone other than the Nazi's; but because they recognized the importance of establishing a legal precedent so it would be there when the "good guys" were under attack[0]. Under this old philosophy, even if the aim of the lawsuit were specifically to help whites, it should still be supported.
By supporting Harvard in this case, you are weakening the legal precedent against racism, and strengthening the legal precedent for it.
Once this precedent is established, it can be used to argue for racism against Jews (it already bears an eerie resemblance to earlier anti-semetic attempts), or gays, or liberals, or redheads.
Sure, this one case won't overturn all our legal protections overnight. But those legal protections did not spring into existence overnight. They grew up through a long sequence of court cases [1] that gradually established our rights. Those cases can be overturned in the same way, and this case is 1 step on that ladder.
[0] The ACLU also recognized the practical importance of sympathetic cases, and so would often make a strategic choice to pursue the most favorable ones, but that is a separate discussion.
[1] And legislation, and shifts in public opinion. But we are talking about a court case, so I am focusing on that aspect of the history.
They used to defend Nazis to make a point of dedication to free speech. Now they openly abandon due process if the accused is a white guy (Kavanaugh) and have recently decided to never protect a Nazi, saying some speech shouldn't be protected. Very sad to see.