I think each line of the TOC can be considered a paragraph, so you could do a "For Each" loop through each line and insert the page break as needed.
After the TOC is created with VBA, try this:
Dim myPar As Paragraph
For Each myPar In ActiveDocument.Paragraphs
myPar.Range.Select
If Selection Like "*" & Chr(9) & "*" And Selection.Paragraphs.Count = 1 Then 'Tests for selection being in TOC and having a single line in the TOC selected
Selection.End = Selection.Start
Selection.InsertBreak Type:=7
End If
Next
You'll probably also have to test the selection to confirm it's a state name. You could do that perhaps with font properties, or you could store the names of states in an array and then loop through the array.