The charts above are from the new Economist / YouGov Poll -- done between March 5th and 8th of a nationwide sample of 1,500 adults (including 1,227 registered voters). The margin of error for adults is 2.7 points, and for registered voters is 2.9 points.
It shows that sympathy in the Ukraine / Russia war lies overwhelmingly with Ukraine according to public opinion in the United States. The public also overwhelmingly believes that Putin has committed war crimes.