Sure. Look at the census figures for 1850 and 1860. The growth in the number of free blacks in most southern states was flat if it did not, in fact, decline. If the laws you are speaking about were rigidly enforced in in Midwestern states as you claim, and states like Illinois and Ohio and Michigan saw increases in the black population of 40 or 50 or 110 percent, then how can you claim that such laws were not enforced in Southern states where the free black population in most states hardly grew at all?
Free blacks were hardly welcomed in Northern states, that is irrefutable. They were disliked, discriminated against, and were denied rights in many states. But it is also irrefutable that blacks were welcomed in Southern states only if they were property. That the were distrusted, disliked, and discriminated against more in Southern states than in Northern ones. That the kinds of laws you complain about in some Northern states also existed in all Southern ones and that they were enforced. And that as bad as things were for free blacks up North, they were significantly worse for free blacks in the South.
To most people in the north, negros were an abstraction - something they heard about and read about and feared. This was particularly true in the Midwest. Ohio once enacted a law to expell the entire black population for example. In the south cruelty and arbitrary laws and practices were somewhat ameliorated by the fact that southerners had to deal with actual people.
Racism was, and to this day still is, more intense in the north.