Aw I didn't think of that.
fc = 'featureclass'
tx = ['City1 State','City2 State','City3 State','City4 State', 'City5 State']
with arcpy.da.UpdateCursor(fc, ['field1']) as cursor:
for row in cursor:
row[0] = " ".join(row[0].split()[:-2])
cursor.updateRow(row)
del cursor
I did notice that it did remove ones like
12345 StreetA St city State -->12345 StreetA St # What I wanted
0 StreetB St --> 0 # This is the issues, I would prefer if it just stayed 0 StreetB St.