You can use Index to Legal Periodicals to find articles about the Court that incorporate statistical analyses.
Use the Advanced Search option. For the first search text box, select "SU Subject Terms" from the adjacent pull-down menu, and enter following exact expression (including the quotation marks and the slash!).
"united states/supreme court"
For the next search text box, leave "Select a Field (optional)" in the adjacent pull-down menu. The enter the following term:
You may also add other search terms to further narrow your results.