If you need to look only at the purpose and importance of racial profiling, there are two main types of argument that you should make.
First, you would need to argue that crime is a serious problem that affects the lives of many Americans in an important way. The ostensible purpose of racial profiling is to fight crime. Therefore, if we are to say that racial profiling is important, crime must be a big deal. You would need to find statistics about the prevalence of crime and you would need to argue that those crime rates are high. You might try to do this by comparing them with past years, or you might simply argue that a given rate of crime is high regardless of how it compares with the past. You might also specify some crimes that you think have the greatest impact on people’s sense of safety in the community. These might be violent crimes as opposed to property crimes, for example. You could look at the rates for those crimes only.
Second, you would need to look at the relevant crimes and connect them to a racial group that could be profiled. It is no good to say that (for example) there are too many robberies and therefore we should do racial profiling if it turns out that there is no one race that is more likely to commit robberies. You have to find that one or more of the crimes that you think is important is so connected to one racial group that racial profiling will help.
So, to argue that racial profiling is important, you must find that crime is a big problem and that the problematic crimes are generally committed by a given racial group. This can help you argue that it is important to allow racial profiling.