I found a solution after all. I had broken the paper into sections, with the TOC in its own section. I reset the margins to the original 1" on all sides for the whole document, then opened the Inspector and went to "Layout." Then, I increased the left Layout Margin by 0.5" in all sections but the TOC. Finally, I highlighted the entire TOC (where the blue line outlines the whole thing) and went to Format > Text > Increase List Indent Level. It shifted the whole TOC over by one Tab amount, which was 0.5". All is well!
Thought I would share this solution in case anyone else has a similar problem. Best of luck!