TheHill article (that YahooNews is citing) only mentions the Dems and GOP. The Harvard CAPS-Harris poll takes the average within a small sample of 2,090 registered voters (Dems, GOP, Independents/Other), including folks who are both familiar and unfamiliar with the indictment ("HEARD" vs. "UNHEARD") in the chart below:
If Donald Trump were convicted and sentenced to jail for his handling of classified documents, would you support or oppose a president pardoning him in the interest of national unity?
Column % GOP DEM IND/OTH HEARD NOT HEARD
Support 80% 30% 48% 54% 49%
(Average is 52.2%)
Oppose 20% 70% 52% 46% 51%
(Average is 47.8%)