A secondary source of information is one that was created later by someone who did not experience first-hand or participate in the events or conditions you're researching
Examples of a secondary source are: Publications such as textbooks, magazine articles, book reviews, commentaries, encyclopedias
In my opinion this is a good idea to do since they are less likely to be bought by the president. Our supreme court should always represent the values of our country and block actions of the Executive branch if deemed illegal.