So, Loving v. Virginia is in the news again, and it caused me to notice that Loving overturned a late 19th Century precedent, Pace v. Alabama. Pace was unanimous, and is basically the same deal as Plessey: Anti-miscegenation laws don't violate the Fourteenth Amendment because all races are equally subject to those laws.
And, in thinking on this, I came upon the grim thought that, if SCOTUS had struck down segregation, or had struck down anti-miscegenation laws, it really could have produced some terrible results. I fear that the backlash would have been so harsh that we would have ended up constitutional amendments permitting miscegenation bans and segregation. Who knows how long it would have taken to get rid of those?
So, with that in mind, what were the aims of the civil rights attorneys in these cases? With the composition of the court at that time, they presumably knew that these were hopeless appeals. Pace was unanimous and Plessey was almost unanimous. And I could imagine that many other civil-rights attorneys thought they were playing with fire, because victory was probably the worst possible outcome. It seems like there's some sort of interesting context that I'm unaware of.
As with any constitutional case in American history, context is key! So let's walk through the legal landscape around these two cases and then see what the mood of the country was. This answer could be expanded upon to discuss the historical context around Reconstruction, but I'll just focus on the legal aspects.
Pace is decided in 1883 and Plessy is decided in 1896, so let's look at the time between roughly the time from the end of the Civil War to 1896. With the Confederate states defeated and still out of the Union, Congress passed the Civil War Amendments, which are ratified by the States between 1865 and 1870. (Herman Belz, The Civil War Amendments to the Constitution: The Relevance of Original Intent, 5 Minn. L. Rev. 115, 115-16 FN 1 [1988].) For purposes of this question, only the Thirteenth and Fourteenth Amendments are relevant (though the Fifteenth, forbidding abridgment of the right to vote based on skin color, also speaks to the general restructuring of race relations going on in the country), so what do they say?
The Thirteenth Amendment says that "[n]either slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction." (U.S. Const., Amend. XIII, Sec. 1.) This is obviously directed towards slavery, with a caveat that you can still order people around if they've been convicted of a crime.
Section 1 of the Fourteenth Amendment is the most important one and contains a few protections for individuals from the states: No state can abridge the privileges or immunities of citizens, no state can deprive an individual of life, liberty, or property without due process of law, and no state can deny to any individual the equal protection of the laws. (US Const. Amend. XIV, Sec. 1).
We can see from these amendments that there was a clear sense in the country after the Civil War that not only should slavery be abolished throughout the country, but that the former slaves should be made citizens and the federal government must protect those former slaves from the states. This intent is clear from Supreme Court cases from the time. Although the Civil Rights Cases held the Civil Rights Act of 1875 unconstitutional, the majority opinion notes that "the one pervading purpose found in all the recent amendments, lying at the foundation of each, and without which none of them would have been suggested - was the freedom of the slave race, the security and firm establishment of that freedom, and the protection of the newly-made freeman and citizen from the oppression of those who had formerly exercised unlimited dominion over him - that each amendment was addressed primarily to the grievances of that race. . . ." (The Civil Rights Cases, 109 US 3, 44 [1883] [internal quotation marks omitted].)
So to get back to the question, what was the aim of the attorneys in these cases? Well, the aim was probably to adhere to the intent of the Civil Rights Amendments and remove any "badge or incident" of slavery from the newly-freed slaves. Three amendments had recently been passed to abolish slavery and create the conditions to permit all newly-freed slaves to participate on an equal footing in society. Why shouldn't the attorneys try to get their clients the rights they were owed?
In my estimation, the attorneys risked relatively little in pursuing their aims. Ultimately, it was not Congress that held back their aims for racial equality at this point, but the Supreme Court. This might be a story for another day, but the Supreme Court has a lot of (what I will charitably call) difficulty in interpreting the Civil Rights Amendments in a way that comports with their original intent. The Slaughterhouse Cases rip the substance out of the Fourteenth Amendment in a way that won't be recovered until Griswold v Connecticut. (The Slaughterhouse Cases, 83 US 36 [1873].) After the Court had sufficiently delayed its recognition and enforcement of these new rights, Congress simply lost the momentum in ensuring racial equality.