Good article.
We don’t know how often Chief Justice John G. Roberts Jr. has withheld a vote to “grant cert” in the 13 years he has held the job, leaving his three generally more conservative colleagues without the necessary fourth vote, because the chief justice worried about either his own or Justice Anthony M. Kennedy’s vote going the wrong way when it came to the merits. How often did discretion rule when the chief’s vote was cast not to hear a case
So as we have known they are not neutral.
So they tend to rule on what they think is best for them and not what the constitution says.