[cnn-photo-caption image= http://i.cdn.turner.com/cnn/2008/images/04/22/art.signs.jpg caption=" Competing political signs are seen in Philadelphia."]
(CNN) - Hillary Clinton and Barack Obama are both holding strong among the most reliable members of their base.
Obama is winning 92 percent of black voters, among his highest margin to date in that demographic. Meanwhile, Clinton is winning among voters 65 and over by a 23 point margin, 61 to 38 percent.
Both candidates have held on to their base, a sign the trench warfare of the last four months could continue.