The Romans weren't really racist in the modern sense. In fact, the City of Rome appears to have been founded by a mixed gang of exiles and outlaws from a number of different tribes. They had to invent their own tribes in the early years in order to run the city as they felt it should be run.
They took slaves, like everyone else, but it wasn't a racial issue. And eventually Britons and Gauls could become Romans.
The Jews were different because they were stubborn about their religion. And they wanted to crucify Jesus because they thought his claim to be the Messiah was blasphemous.
Pontius Pilate had to agree for political reasons, because if he didn't go along he would have lost his job, accused by the Jews of being soft on revolutionaries.
P.S. Jews could become Roman citizens, too, and many of them were.
St. Paul was a Roman citizen, which was why he had to be taken back to Rome to be judged.
The Roman's weren't racist in the modern sense, but they certainly thought of the Jews as a separate race. But their slavery was a matter of taking the spoils of war. There were slaves of every race. In our culture, only the blacks were thought of as a servile race. Sort of the same way that the English though of the Irish.